Cell freezing system, vial holder and cell freezing method

Abstract

A vial holder having a bulk portion containing a metal having good thermal conductivity as a main body is suitable for use in a gas-cooled refrigerator. More than one hole is formed in the block-shaped part of the vial rack, and the vial can be inserted into the hole. The gas-cooled refrigerator cools the lump portion of the vial holder disposed in the cooling chamber in a state in which the vial is inserted by cold air, and the cooled lump portion cools the vial and the cell suspension inside the vial through the inner surface of the hole. The vial holder of the present invention has a bulk portion as the main body and thus is suitable for cooling with gas.

Description

Technical Field

[0001] The present invention relates to a cell freezing system for appropriately freezing cells contained in a vial in the form of a cell suspension, a vial stand used for the cell freezing system, and a cell freezing method using the cell freezing system. Background Art

[0002] In the development of cell-based pharmaceuticals, etc., it is required to construct a cell freezing system that can rapidly freeze and preserve a large number of cells. In particular, with regard to cooling of cells, research is underway on how to reduce damage to cells during freezing.

[0003] In more detail, first, regarding the temperature reduction rate when freezing cells, constant cooling at a specific preferred temperature reduction rate (about 1°C per minute) is recommended (for example, Patent Document 1). This constant cooling can alleviate the formation of ice crystals in cells observed under rapid cooling, and can also alleviate the excessive dehydration in cells observed under slow cooling, thereby reducing the damage caused by these situations.

[0004] However, when a cell suspension is placed in a vial and cooled by a freezer to freeze it, a temperature rise due to latent heat (coagulation latent heat) released from the cell suspension during freezing is apparent. It has been reported that constant cooling at the preferred temperature reduction rate as described above is hindered by the temperature rise due to this latent heat (e.g., Non-Patent Document 1).

[0005] Fig.18 This is a graph schematically showing the temperature rise due to the latent heat released when a cell suspension is frozen (hereinafter, sometimes simply referred to as "temperature rise due to latent heat"). If a vial containing a cell suspension is placed in a freezer and cooled at a constant output such that the temperature decrease rate reaches about 1°C per minute, the liquid (the solvent of the cell suspension, the liquid in the cells) releases latent heat when it is frozen, such as Fig.18 As shown in the temperature change curve of , the temperature of the cell suspension temporarily rises near the freezing point. Due to this temporary temperature rise, the constant cooling at the above-mentioned preferred temperature reduction rate is hindered, and the cells are damaged by ice crystals or concentration increase.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: U.S. Patent Application Publication No. 2005 / 0241333A1

[0009] Patent Document 2: U.S. Patent No. 7870748B2

[0010] Patent Document 3: U.S. Patent No. 8794013B2

[0011] Non-patent literature

[0012] Non-patent document 1: Charles J. Hunt, "Technical Considerations in the Freezing, Low-Temperature Storage and Thawing of Stem Cells for Cellular Therapies", Transfus Med Hemother 2019; 46: 134-149. DOI: 10.1159 / 000497289 Summary of the invention

[0013] Problems to be solved by the invention

[0014] In order to freeze a large number of vials containing cell suspensions, it is advantageous to use a gas cooling type freezer that can cool even a wide cooling chamber. In addition, in order to arrange a large number of vials in the cooling chamber, it is preferred to use a vial rack. As the vial rack, a frame-type vial rack (hereinafter also referred to as a "frame-type rack") has been considered to be preferred (for example, Patent Document 2, etc.). The frame-type rack fully opens the interior of the vial rack to the outside world like a conventionally known test tube rack, thereby fully exposing the body of the vial to the outside world (for example, FIG10 of Patent Document 1, FIG2 to FIG5 of Patent Document 2, etc.). That is, if the open structure of the frame-type rack is used, the cooling gas enters the vial rack from the side, cools the vial and flows out of the vial rack, so it is considered that preferred cooling using gas can be performed. As specific structural examples of the frame-type vial rack, those described in FIG10 of Patent Document 1 can be cited.

[0015] Fig.19 This is a diagram showing an example of a gas cooling type refrigerator 110 and an example of a frame 120 to be arranged inside the cooling chamber 111 thereof. The gas cooling type refrigerator 110 manages to preferably send a low-temperature cooling gas (hereinafter, the low-temperature cooling gas is also referred to as cold air) capable of freezing a cell suspension into the cooling chamber. On the other hand, the frame 120 is formed as shown in FIG10 of Patent Document 1, so that the cold air sent into the cooling chamber preferably flows into the frame and contacts the vials, and then preferably flows out of the frame. Fig. 20, the flow of cooling gas in the cooling chamber is illustrated in FIG. 1 , and the gas cooling type refrigerator 110 operates in the following manner, that is, cold air having a temperature lower than the freezing point of the cell suspension is caused to flow into the cooling chamber 111 and circulate by the fan 112, and the cold air is blown to the vials 130 in the frame 120 to freeze the cell suspension in the vials. This freezing process using cold air is specifically described in, for example, Patent Document 1.

[0016] As described above, in the past, when the vial rack is placed in a gas cooling type refrigerator, it is considered that the cold air sent into the cooling chamber contacts the vials as much as possible, and therefore it is necessary to use a frame type rack with good ventilation in which the body part of the vials is exposed. Such a combination of a gas cooling type refrigerator and a frame type rack is also described in the above-mentioned Patent Document 2, for example.

[0017] However, the present inventors conducted a detailed study on the configuration of the cell freezing system (a configuration using a gas cooling type refrigerator and a frame) that is considered suitable for mass production, and found the following problems.

[0018] When suppressing the temperature rise caused by latent heat by rapid cooling, it is necessary to make the timing of latent heat generation and the start of rapid cooling consistent (for example, Patent Document 3). However, when multiple vials are cooled simultaneously in the same cooling chamber during mass production, the timing of latent heat generation varies from vial to vial, resulting in deviations. Therefore, it is known that it is difficult to absorb the latent heat of multiple vials at one time by rapid cooling and make the temperatures of each vial the same. That is, when multiple vials are cooled simultaneously, the problem of temperature rise caused by latent heat is not fully solved. There is a trade-off relationship between [the high density of vial configuration accompanying the efficiency of mass production] and [the ability to cool multiple vials equally or the ability to perform heat exchange equally with all vials]. Therefore, it is known that if multiple vials are to be forcibly cooled, the number of vials whose temperature rise due to latent heat is not suppressed will increase.

[0019] As described above, in previous mass-produced cell freezing systems, even if one wanted to cool multiple vials at a time, the temperatures of the cell suspensions in the vials were different from one another, and depending on the vial, there might be cell suspensions that did not reach the freezing temperature, so it was difficult to achieve cooling at a specific temperature reduction rate.

[0020] An object of the present invention is to provide a cell freezing system, a vial rack, and a cell freezing method having a novel structure capable of alleviating the above-mentioned temperature-related problems when cooling a plurality of vials at a time.

[0021] Means for solving problems

[0022] The main structure of the present invention is as follows.

[0023] [1] A cell freezing system for freezing the cell suspension by cooling one or more vials containing a cell suspension while the vials are inserted into a vial rack,

[0024] The cell freezing system has:

[0025] A gas-cooled refrigerator having a cooling chamber, and

[0026] A small bottle rack arranged in the cooling chamber;

[0027] The vial holder has a block portion made of metal with good thermal conductivity as a main body, and the block portion has one or more holes for inserting into the body portion of the vial at least to the liquid level of the cell suspension;

[0028] When in use, the gas-cooled refrigerator cools the vial rack with the vials inserted therein, which is arranged in the cooling chamber, using cooling gas. The cooled vial rack cools the vials and the cell suspension in the vials through the inner surface of the hole of the block portion.

[0029] [2] The cell freezing system according to [1] above, wherein the thermal conductivity of the metal having good thermal conductivity is 100 (W / (m·K)) or more.

[0030] [3] The cell freezing system according to [1] or [2] above, wherein the metal with good thermal conductivity is aluminum, aluminum alloy, copper, copper alloy, magnesium or magnesium alloy.

[0031] [4] The cell freezing system according to any one of [1] to [3] above, wherein the basic shape of the block portion of the vial rack is a three-dimensional shape having a flat upper surface,

[0032] A plurality of the holes extend from the upper surface toward the interior of the block portion,

[0033] In the upper surface, openings of the plurality of holes are arranged in a prescribed configuration pattern.

[0034] [5] The cell freezing system according to [4] above, wherein the three-dimensional shape is a rectangular parallelepiped or a cube.

[0035] [6] The cell freezing system according to any one of [1] to [5] above, wherein the outer basic shape of the body portion of the vial is cylindrical, and the inner space of the hole for inserting the body portion is cylindrical,

[0036] The difference between the inner diameter of the hole and the outer diameter of the body portion of the vial is 0.1 to 3 mm.

[0037] [7] The cell freezing system according to any one of [1] to [6] above, wherein the inner surface of the hole is subjected to surface treatment so that the inner surface has a higher emissivity.

[0038] [8] The cell freezing system according to any one of [1] to [7] above, wherein the hole is a bag-shaped hole having a bottom surface inside,

[0039] On the inner surface of the hole, one or more grooves are provided from the opening of the hole to the bottom surface. When the main body of the vial is inserted into the hole, the air in the hole is discharged to the outside through the grooves.

[0040] [9] The cell freezing system according to [8] above, wherein the groove provided on the inner peripheral surface of the above-mentioned hole is integrally connected with the groove provided in the hole located at an adjacent position to form a slit, thereby connecting the adjacent holes to each other.

[0041]

[10] A cell freezing system according to any one of [1] to [9] above, wherein a radiator is provided on the outer surface of the block-shaped portion to increase the efficiency of heat exchange between the block-shaped portion and the cooling gas in the cooling chamber.

[0042]

[11] A cell freezing system according to any one of [1] to

[10] above, wherein the interior of the block portion is provided with one or both of a heat pipe and a vapor chamber so as to increase the thermal conductivity between the outer surface of the block portion and the periphery of the hole.

[0043]

[12] A cell freezing system according to any one of [1] to

[11] above, wherein the block portion is provided with one or both of a heat pipe and a temperature equalizing plate so that the heat of the lower surface of the block portion can be conducted to the side of the block portion with higher efficiency.

[0044]

[13] A cell freezing system according to any one of [1] to

[12] above, wherein a temperature sensor for measuring the temperature of the block portion is installed on the block portion of the vial rack, and the temperature sensor is configured to communicate temperature-related data with a control unit of the gas-cooled refrigerator or with an external device when the vial rack is arranged in a cooling chamber of the gas-cooled refrigerator.

[0045]

[14] The cell freezing system according to any one of [1] to

[13] above, wherein the cooling chamber has an indoor space large enough to accommodate a plurality of vial racks.

[0046] One or both of a heater and a Peltier element are provided at the block portion of each vial rack or at the location for each vial rack in the cooling chamber, so that the temperature of each vial rack can be adjusted individually.

[0047]

[15] The cell freezing system according to any one of [1] to

[14] above, wherein the gas cooling refrigerator is a program refrigerator that can change the cooling capacity according to a preset program,

[0048] The programmed freezer is configured to increase cooling capacity during the period of releasing latent heat so as to suppress a rise in temperature of the cell suspension caused by release of latent heat during freezing of the cell suspension.

[0049]

[16] A vial stand, which is a vial stand used in the cell freezing system described in any one of [1] to

[15] above,

[0050] The main body of the invention comprises a block-shaped part made of metal with good thermal conductivity. The block-shaped part has one or more holes for being inserted into the main body of a vial containing a cell suspension at least to the liquid level of the cell suspension.

[0051]

[17] The vial rack according to

[16] above, wherein a heat sink is provided on the outer surface of the block-shaped portion so as to further improve the efficiency of heat exchange between the block-shaped portion and the cooling gas.

[0052]

[18] The vial rack according to

[16] or

[17] , wherein one or both of a heat pipe and a temperature equalizing plate are provided inside the block portion so that the thermal conductivity between the outer surface of the block portion and the periphery of the hole is further increased.

[0053]

[19] A vial rack according to any one of

[16] to

[18] above, wherein the block portion is provided with one or both of a heat pipe and a temperature equalizing plate so that the heat of the lower surface of the block portion can be more efficiently transferred to the side surface of the block portion.

[0054]

[20] A cell freezing method, which is a cell freezing method using the cell freezing system described in any one of [1] to

[15] above, the cell freezing method comprising:

[0055] A step of preparing a vial rack of the cell freezing system, into which a vial containing a cell suspension as a freezing target is inserted; and

[0056] A cooling step of cooling the vial rack having the vials inserted therein in a cooling chamber of a gas-cooled refrigerator of the cell freezing system to cool and freeze the cell suspension;

[0057] In the cooling step, the gas-cooled refrigerator uses cooling gas to cool the block portion of the vial rack to a temperature at which the cell suspension is frozen. The cooled block portion cools the vial and the cell suspension in the vial through the inner surface of the hole, thereby freezing the cell suspension.

[0058] Effects of the Invention

[0059] In the cell freezing system and cell freezing method of the present invention, unlike the previous system, the cold air in the cooling chamber of the gas-cooled refrigerator is not directly blown to the vial, but a special vial rack made of metal with good thermal conductivity is used to cool the block portion as the main body of the vial rack by cold air. The vial is inserted into the hole of the block portion, and the inner surface of the hole surrounds the main body of the vial. Therefore, the cooled block portion quickly absorbs heat from the vial and the cell suspension inside it mainly through heat conduction and / or heat radiation. That is, in the present invention, the gas-cooled refrigerator uses a gas-cooled vial rack, and the vial rack cools the vial and its contents through heat conduction and heat radiation. Thereby, the temperature rise caused by latent heat is preferably suppressed, and the disturbance of the cooling rate is also preferably suppressed. Even if multiple vials are accommodated in one vial rack, the difference in cooling conditions between the vials can be made smaller, and multiple vials can be cooled in a more equal state.

[0060] In the present invention, even if the gas-cooled freezer is a device whose cooling capacity cannot be changed, as long as the heat capacity of the block-shaped portion of the vial rack is large enough, the latent heat emitted by each vial can be preferably absorbed, and the temperature of each vial can be made uniform. However, in a preferred embodiment of the present invention, it is recommended to use a program freezer that can change the cooling capacity as a gas-cooled freezer. If a program freezer is used, the cooling capacity can be increased according to the average time point of freezing the cell suspension in each vial, thereby allowing the block-shaped portion of the vial rack to more quickly remove the latent heat absorbed by each vial using cold air, and the temperature rise caused by the latent heat and the disturbance of the cooling rate can be more preferably suppressed.

[0061] The vial rack of the present invention is a material used to constitute the cell freezing system of the present invention, and has a structure in which a hole for inserting a vial is provided in a metal block portion with good thermal conductivity. According to this structure, as long as the metal block portion with good thermal conductivity is cooled by a cooling gas, the vial (containing a freezing object) inserted into the hole of the block portion can be cooled while absorbing heat efficiently through the metal block portion with good thermal conductivity. As a result, the freezing object can be cooled and frozen while suppressing the temperature rise caused by the release of latent heat. The vial rack is preferably used to cool a plurality of vials using a low-temperature cooling gas, and its usefulness becomes particularly significant when used in the cell freezing system and cell freezing method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 : Figure 1 This is a cross-sectional view schematically showing an example of the structure of the cell freezing system and cell freezing method of the present invention. This figure shows the appearance of the vial but does not show the cross section (the same applies to other figures). The hatching showing the cross section is only applied to the vial rack.

[0063] Figure 2 : Figure 2 This is a diagram showing a portion of the upper surface of the block portion of the vial rack of the present invention, and is a partial enlarged diagram illustrating the arrangement pattern of holes on the upper surface. The dot-dash line is a line passing through the center of the hole, and is used to easily understand the arrangement pattern of the holes.

[0064] Figure 3 : Figure 3 : is a perspective view showing a preferred embodiment of the vial rack of the present invention ( Figure 3 (a)) and local enlarged image ( Figure 3 (b) ) and shows an example of a spacer provided in the hole. Figure 3 In (a), for the sake of explanation, the spacer is removed from one hole and shown in an exploded view, and for the sake of explanation, vials are inserted into six holes. Figure 3 (b) is a partially enlarged view of the hole into which the vial is inserted, viewed from the upper surface, and is a view for explaining the size of the protrusion of the spacer. Figure 3 In (b), the block portion and the main body of the vial are hatched to facilitate understanding of the regions.

[0065] Figure 4 : Figure 4 This is a cross-sectional view showing a preferred embodiment of the vial holder in the present invention, and shows another example of the spacer provided in the hole. The hatching showing the cross section is applied only to the vial holder and the protrusion.

[0066] Figure 5 : Figure 5 It is a perspective view showing a preferred embodiment of the vial holder in the present invention, and shows an example of blackening the inner surface of the hole. Figure 5 (a) shows a state where the inner surface of the hole is blackened. Figure 5 (b) shows a state where the inner surface of the hole is blackened.

[0067] Figure 6 : Figure 6 The diagram shows a part of the upper surface of the block portion of the vial holder in the present invention, is a partial enlarged view showing the opening of one hole and its surroundings, and shows an example of a groove provided on the inner surface of the hole.

[0068] Figure 7: Figure 7 This is a perspective view showing an example of a vial holder having a preferred groove provided on the inner wall of the hole in the present invention.

[0069] Figure 8 : Figure 8 is a more detailed description Figure 7 Figure 1 shows a vial rack. Figure 8 (a) is a top view of the vial rack, Figure 8 (b) is the observation Figure 8 (a) is a perspective view of a cross section of the vial rack when it is cut along the cutting line AA.

[0070] Fig. 9 : Fig. 9 This is a schematic diagram showing an example of a mode in which a heat sink is provided on the outer surface of the block-shaped portion of the vial holder in the present invention.

[0071] Fig.10 : Fig.10 This is a perspective view showing an example of a multi-layer rack for arranging a plurality of vial racks in a cooling chamber according to the present invention. Fig.10 (a) shows a case where the vial racks in the multi-layer rack have sufficient clearance between each other. Fig.10 (b) shows a passage of cold air which is important when the gaps between the vial racks in the multi-layer rack are narrow and the multi-layer racks are densely packed.

[0072] Fig.11 : Fig.11 This is a schematic diagram showing an example of a mode in which a temperature equalizing plate is provided inside a block-shaped portion of a vial rack in the present invention. Fig.11 (a) is an exploded view showing a method of installing a temperature equalizing plate in a block-shaped portion (only the top plate is disassembled and removed in order to observe the interior). Fig.11 (b) is an exploded view showing a state where the temperature equalizing plate is removed from the block portion.

[0073] Fig.12 : Fig.12 This is a diagram illustrating an embodiment of the present invention in which a temperature equalizing plate and a heat sink are provided on a block portion of a vial rack. Fig.12 (a) is a side view illustrating a mode in which a temperature equalizing plate is provided on the lower surface of the block-shaped portion. Fig.12 (b) is an exploded view illustrating a mode in which the temperature equalizing plate is exposed at the bottom of the hole of the block portion.

[0074] Fig.13 : Fig.13 This is a perspective view showing an example of a mode in which a heater and / or a Peltier element are provided so that the temperature of a plurality of vial racks can be individually controlled in the present invention.

[0075] Fig.14 : Fig.14Schematic diagram showing the arrangement of four racks in a cooling chamber in an embodiment of the present invention. In the figure, each rack is simply depicted for the purpose of explaining the arrangement of the racks, but the actual racks are as follows: Fig.10 As shown in (a), the small bottle racks arranged on each layer are frame-structured racks that can fully contact cold air, and the small bottle racks are arranged on each layer. Fig.14 In (b), only the small bottle rack 20B of the comparative example is hatched for distinguishing the display.

[0076] Fig.15 : Fig.15 This is a schematic diagram showing the structure of the shelf plates of each layer of the rack arranged in the cooling chamber in the embodiment of the present invention. This figure is a view of the plate surface, and the circular body part of the vial is superimposed to show the positional relationship between the through hole and the vial.

[0077] Fig.16 : Fig.16 Schematic diagram showing the arrangement pattern of vials provided with thermocouples for measuring the internal temperature in an embodiment of the present invention. The figure shows the upper surface of each of the vial racks of four racks when the inside of the cooling chamber is viewed from above.

[0078] Fig.17 : Fig.17 This is a graph showing the temperature rise due to the latent heat when the vials are cooled using the vial rack used in the present invention and the conventional frame-type vial rack in the examples of the present invention.

[0079] Fig.18 : Fig.18 This is a graph schematically showing the state of temperature rise due to latent heat release when a cell suspension is frozen.

[0080] Fig.19 : Fig.19 This is a diagram showing an example of a conventional gas cooling type refrigerator and an example of a frame type frame to be arranged inside the cooling chamber thereof.

[0081] Fig. 20 : Fig. 20 This is a diagram illustrating the flow of cooling gas in a cooling chamber in a combination of a conventional gas cooling type refrigerator and a frame type vial rack. DETAILED DESCRIPTION

[0082] First, the cell freezing system of the present invention will be described.

[0083] like Figure 1As schematically shown in FIG. 1 , the cell freezing system is a system for freezing the cell suspension 31 by cooling the vials 30 containing the cell suspension 31 by a gas cooling type refrigerator 10 in a state where one or more vials 30 containing the cell suspension 31 are inserted into a vial rack 20. Hereinafter, the operation of (cooling the vials containing the cell suspension) is also referred to as (cooling the vials). In this case, cooling the vials means cooling not only the vials but also the cell suspension inside. The cell freezing system is configured to include: a gas cooling type refrigerator 10 having a cooling chamber 11, and a vial rack 20 arranged in a manner that allows access to the cooling chamber 11. The illustration of a door that can be opened and closed for sealing the cooling chamber 11 and a cooling device for conveying cold air (low-temperature cooling gas that can freeze the cell suspension) is omitted. The vial rack 20 has a block portion 21 made of a metal with good thermal conductivity such as aluminum as a main body. The block portion 21 has one or more holes 22, and the holes 22 are used to insert at least the main body portion of the vial 30. Figure 1 In the example, there are 4 holes, and in order to easily understand the inner surface of the hole, no vial is inserted into one hole. In the actual method, in the block part 21, it is also possible to Fig.19 The plurality of holes are arranged in various configuration patterns as in the conventional frame rack shown in the figure. The arrangement of the holes can be interchangeable with the arrangement of the holes in the conventionally known vial rack (in which the plurality of holes are arranged at predetermined positions so that the vials can be loaded and unloaded by a robot arm). It is optional to insert the vials into all or part of the plurality of holes.

[0084] When the cell freezing system is used, the vial rack 20 in which the vials 30 are inserted is arranged in the cooling chamber, and the cooling function of the gas cooling type refrigerator 10 is operated. In the cooling chamber 11 of the gas cooling type refrigerator 10, as shown in FIG. Figure 1 As shown in the example, the cold air 12 cools the vial rack 20 (especially the block portion 21). The thick arrow C1 represents the heat released from the block portion 21 into the cold air. In addition, the thick dotted line showing the cold air 12 represents the flow of the cold air, but does not limit the flow path. The cooled vial rack 20 quickly cools each vial 30 and the cell suspension 31 therein through the inner surface of each hole 22 of the block portion 21 (i.e., through heat radiation and / or heat conduction). As long as the temperature of the cold air 12 is a low temperature that can freeze the cell suspension, the cell suspension in each vial is also quickly cooled and frozen. Thereby, even in a state where a plurality of vials are configured, cooling can be performed under a state in which deviations in cooling conditions are suppressed, and the cell suspension in each vial can be frozen by suppressing the preferred temperature reduction caused by the temperature rise caused by latent heat, thereby reducing cell damage.

[0085] (Small bottle)

[0086] In the present invention, "vial" refers to a container that can hold a cell suspension as a freezing object. The vial includes not only bottles for holding pharmaceuticals and cell suspensions, but also test tubes, centrifuge tubes and other containers. In addition, the vial also includes ampoules, syringes, straws for freezing and open containers. The vial can be designed and manufactured for the present invention, or it can be a commercially available product (including standard products specified in ISO 8362-1, etc.). The overall shape of the vial and the shape of the main body are not particularly limited, and can be any shape such as a prism or a flat plate, but the most common external shape of its main body is a cylinder. The following specifically describes the present invention for the case where the external shape of the main body of the vial is a cylinder, but in the case where the external shape is other than a cylinder, the present invention can also be implemented by appropriately establishing a correspondence between the structure described below and the structure of the case other than a cylinder.

[0087] In the present invention, the "body part of the vial" refers to the main part used to contain the cell suspension and is Figure 4 In the example of (a), as shown by symbol 30a, it is the part below the shoulder of the container. The chamfered part with a radius between the shoulder and the bottom can be included in the main body. In the shape where the mouth is not narrowed (without the shoulder and the whole is a straight cylindrical shape), the mouth can also be included in the main body. In addition, those whose lower end of the main body is hemispherical, such as a common round-bottomed test tube, and those whose lower end of the main body is conical, such as a conical test tube, and the hemispherical and conical parts of their lower ends can also be included in the main body.

[0088] (Material of the container part of the vial)

[0089] The material of the container portion of the vial is not particularly limited, and may be glass (e.g., borosilicate glass) which is a material for bottles for enclosing medical drugs, synthetic resins (e.g., thermoplastic resins, thermosetting resins, more specifically polyolefin resins or cyclic polyolefin resins such as polypropylene resins, polyethylene resins, and ethylene-propylene copolymers, polystyrene resins such as acrylonitrile-butadiene-styrene resins, polycarbonate resins, polyethylene terephthalate resins, methacrylic resins such as polymethyl methacrylate resins, vinyl chloride resins, polybutylene terephthalate resins, polyarylate resins, polysulfone resins, polyethersulfone resins, polyetheretherketone resins, polyetherimide resins, fluorine resins such as polytetrafluoroethylene, acrylic resins such as polymethylpentene resins, polyacrylonitrile, cellulose resins such as propionate resins, etc.), and the like, which are known materials that can be used for containing and freezing cell suspensions. Glass is a more preferred material than synthetic resins because of its higher thermal conductivity, but the risk of breakage is high during the cooling process and low-temperature storage. On the other hand, although the thermal conductivity of synthetic resin is lower than that of glass, the risk of breakage is low and it is a material preferred in practical use. Among the above synthetic resins, cyclic polyolefin resins (ring-opening polymerization hydrogenated resin (COP), cyclic olefin copolymer (COC)) are generally used.

[0090] (Cap of the small bottle)

[0091] Small bottle Figure 1 As shown, it is preferred to have a cap that can seal the inside. The cap may have various structures made of various known materials depending on the purpose of use, such as a plug body, a screw cap, a cap fixed to the mouth of the vial by riveting (aluminum crimp cap, etc.), a plastic cap (for example, a cap that covers the mouth of the vial and can be fixed to the mouth by just pressing (RayDyLyo (registered trademark) manufactured by Araymondlife, PLASCAP (registered trademark) manufactured by Daikyo Seiko Co., Ltd.), etc.), a cap with a septum in the center, a cap that can reseal the puncture hole by laser after the filling needle is punctured and the contents are filled (AT-Closed Vial (registered trademark) manufactured by Aseptic Technologies), etc. The mouth of the vial may correspond to the sealing structure of the cap, and conversely, the sealing structure on the inside of the cap may correspond to the shape of the mouth of the vial. The relationship between the outer diameter of the cap and the outer diameter of the body of the vial may vary depending on the capacity of the vial, the structure of sealing the mouth of the vial, etc., and the outer diameter of the cap may be smaller, the same, or larger than the outer diameter of the body of the vial.

[0092] (Volume of vial and dimensions of body)

[0093] When the outer shape and inner shape of the main body of the vial are cylindrical, the volume of the vial (the volume of the internal space of the vial), and the dimensions of the outer side of the main body (outer diameter, length in the direction of the central axis) are not particularly limited. As a general volume, about 0.2 to 250 mL can be exemplified (mL means milliliter). In this case, the outer diameter of the main body is about 6 to 60 mm, and the length of the main body in the direction of the central axis is about 20 to 200 mm. In addition, as a more general volume, about 1 to 50 mL can be exemplified. In this case, the outer diameter of the main body is about 10 to 50 mm, and the length of the cylindrical part in the direction of the central axis is about 35 to 120 mm.

[0094] These values ​​are general examples, and the specifications of the body of the vial including the volume, the outer dimensions, the thickness of the wall, etc. can be freely selected according to the user's requirements, etc. In addition, the specifications of the body of the vial can also be in accordance with the vial standard such as ISO 8362-1.

[0095] (Cell suspension as a freezing target)

[0096] In the present invention, the cell suspension that can be used as the object of freezing is not particularly limited, and the usefulness of the present invention becomes more significant as long as it is a liquid in which cells that have the problem of being damaged by the temperature rise caused by the latent heat during freezing are dispersed. The cell suspension can be prepared by dispersing the desired cells in the cell preservation solution described later.

[0097] (cell)

[0098] The types of cells that can be used in the present invention are not particularly limited, and may be any of microorganisms, bacteria, animal cells, and plant cells, preferably animal cells, for example, mammals (mice, rats, guinea pigs, hamsters, rabbits, cats, dogs, sheep, pigs, cattle, horses, goats, monkeys, humans, etc.), birds (chickens, ducks, etc.), reptiles, amphibians, fish (zebrafish, rice field fish, etc.) and other vertebrates, insects (silkworms, moths, fruit flies, etc.) and other invertebrate cells. Animal cells are more preferably mammalian cells. When using animal cells, for example, cell strains of animal cells can be used, cells derived from organs, tissues or body fluids (including blood, lymph and semen) collected from animals such as mammals can also be used, or transformed cells obtained by genetic engineering techniques can also be used. As cells, it can be any of undifferentiated cells or differentiated cells, and it can also be any of somatic cells or germ cells.

[0099] Specifically, the following cells can be exemplified. As somatic cells, for example, (1) neural stem cells, hematopoietic stem cells, mesenchymal stem cells, dental pulp stem cells and other tissue stem cells (somatic stem cells), (2) tissue precursor cells, (3) lymphocytes such as B cells, T cells, NK cells, (4) epithelial cells, retinal pigment epithelial cells, visual cells, endothelial cells, muscle cells, fibroblasts (skin cells, etc.), hair cells, hepatocytes, gastric mucosal cells, intestinal cells, spleen cells, pancreatic cells (pancreatic exocrine cells, etc.), nerve cells, brain cells, lung cells, kidney cells and fat cells and other differentiated tissue cells, etc. can be mentioned. As reproductive cells, for example, sperm, spermatocytes, spermatocytes, egg cells, oocytes, etc. can be mentioned. In addition, examples of pluripotent stem cells include embryonic stem cells (ES cells), embryonic stem cells derived from cloned embryos obtained by nuclear transplantation (ntES cells), sperm stem cells (GS cells), embryonic germ cells (EG cells), artificial pluripotent stem cells (iPS cells), and pluripotent cells derived from cultured fibroblasts or medullary stem cells (Muse cells).

[0100] (Cell preservation medium)

[0101] The cell preservation solution that can be used in the present invention is a solution for preserving cells at low temperatures, preferably below -80°C, more preferably below -140°C, and further preferably below -196°C, and is not particularly limited, but physiological saline, various buffers, microorganisms, cell culture medium, organ preservation solution, commercially available cryopreservation solution, etc. can be used alone or in combination. In addition, serum, serum replacement, various drugs necessary for cell maintenance (for example, ROCK inhibitors, etc.), various vitamins, various amino acids, various cytokines, various hormones, various growth factors, various extracellular matrices, various cell adhesion molecules, antibiotics, stem cell factors, and cryoprotectants can be added to the cell preservation solution as needed.

[0102] Examples of the cell culture medium include StemFit (e.g., StemFit AK03N, StemFit AK02N) (Ajinomoto Co., Ltd.), PECM (Primate ES Cell Medium), GMEM (Glasgow Minimum Essential Medium), IMDM (Iscove's Modified Dulbecco's Medium), 199 medium, Eagle's Minimum Essential Medium (EMEM), αMEM, Dulbecco's modified Eagle's Medium (DMEM), Ham's F12 medium, RPMI 1640 medium, Fischer's medium, and mixed medium thereof.

[0103] As serum, for example, fetal bovine serum (FBS), fetal calf serum (FCS) and the like can be cited. As serum substitutes, for example, substances that suitably contain albumin (for example, lipid-rich albumin, albumin substitutes such as recombinant albumin, plant starch, dextran and protein hydrolysate, etc.), transferrin (or other iron transporters), fatty acids, insulin, collagen precursors, trace elements, 2-mercaptoethanol, 3'-thioglycerol or their equivalents can be cited. The serum substitute can be prepared, for example, by the method described in WO 98 / 30679. In addition, for greater convenience, commercial products can also be used. As the commercially available substances, Knockout (trademark) Serum Replacement (KSR), Chemically-defined Lipid concentrated and Glutamax (Invitorogen) can be cited.

[0104] Examples of commercially available cryopreservation solutions include STEM-CELLBANKER (registered trademark) (ZENOAQ) and the like.

[0105] The cryoprotectant that can be used in the present invention refers to a substance that has a high affinity with water molecules and has a high effect of inhibiting ice crystal growth when dissolved in a cell preservation solution, and specifically includes, for example, dimethyl sulfoxide (DMSO), glycerol, trehalose, sucrose, ethylene glycol, polyethylene glycol, propylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butylene glycol, isoprene glycol, dipropylene glycol, polyvinyl pyrrolidone, carboxylated polylysine, poloxamer, etc. The concentration of the cryoprotectant in the cell preservation solution can be appropriately set according to the type of cryoprotectant, for example, it can be 2% to 20% by mass, 5% to 15% by mass, etc.

[0106] As an example of a method for preparing a cell suspension, the cell as illustrated above is separated from an organism by utilizing enzyme treatment, etc., or primary cells and cell strains are amplified by cultivation and dispersed by utilizing enzyme treatment, etc., and a cell preservation solution as illustrated above is added to the cells obtained. At this time, concentration, cleaning, liquid exchange, etc. can be carried out by a centrifuge, a semipermeable membrane, etc., and the concentration of each component in the cell density and the suspension can also be appropriately adjusted. The cell in the cell suspension can be one kind or a mixture of more than two kinds. In addition, the cell morphology in the cell suspension can be a single cell state, a plurality of aggregations, or a micro-tissue of several mm or less such as a spheroid. The cell suspension prepared by the above operation can also be dispensed in the sterilized container illustrated above, and then can also be sealed by the sterilized lid illustrated above. The cells prepared in this way are provided in the freezing process performed using the cell freezing system of the present invention, etc., and are provided for preservation before use.

[0107] The cell suspension obtained by such a step is preferably used clinically as a cell medicine, and it is ideal that the above step is performed aseptically.

[0108] (Small bottle rack)

[0109] like Figure 1 As shown, in the present invention, the vial rack is arranged so that it can enter and exit the cooling chamber of the gas-cooled refrigerator in a state where the vials are inserted. The number of vials inserted into the vial rack is one or more, preferably a plurality. A combination of [the size of each part of the vial rack, especially the size of each part of the block-shaped part], [the size, number, and arrangement pattern of the vials arranged in the block-shaped part], and [the size of the cooling chamber and the size of the opening of the cooling chamber] is selected so that the vial rack in a state where the vials are inserted can enter and exit the space in the cooling chamber.

[0110] (Blocky part of vial rack)

[0111] The vial rack used in the present invention has a block-shaped portion (support portion) containing a metal with good thermal conductivity as the main body. The block-shaped portion has a hole for inserting a vial as an essential element, and in a preferred embodiment, it also has additional elements such as a handle (a protrusion for holding) and a foot. Therefore, the basic form of the body (main body) when all the additional elements are removed from the vial rack and the hole is filled with a metal with good thermal conductivity is a metal block. In the present invention, the metal block as the main body is referred to as a "block-shaped portion containing a metal with good thermal conductivity". When the vial rack is manufactured by casting, etc., the block-shaped portion has a hole from the beginning. By giving the block-shaped portion containing a metal with good thermal conductivity a structure of a hole for inserting a vial, even if the temperature of the cell suspension in the vial rises during cooling, the block-shaped portion quickly absorbs heat from the vial and the cell suspension through the inner surface of the hole, and the heat is quickly conducted to the outer surface of the block-shaped portion. The heat reaching the outer surface of the block-shaped portion is absorbed by the cold air in the cooling chamber.

[0112] (Metals with good thermal conductivity and their thermal conductivity)

[0113] The thermal conductivity of the metal with good thermal conductivity constituting the block portion is preferably 100 (W / (m·K)) or more, more preferably 150 (W / (m·K)) or more, and preferably has the highest possible thermal conductivity. In addition, the metal with good thermal conductivity preferably has the highest possible mechanical strength. Regarding the thermal conductivity of the main metals with good thermal conductivity, for example, according to the "Distributed Thermophysical Property Database" operated by the National Research and Development Corporation Advanced Industrial Science and Technology on the Internet website, it is roughly aluminum; 226~237, magnesium; 155~156, copper; 386~402, zinc; 116, gold; 318, silver; 429 (all are values ​​near room temperature, unit is (W / (m·K))).

[0114] As a preferred metal with good thermal conductivity that is inexpensive and has good processability, aluminum, aluminum alloys, copper, copper alloys, magnesium, or magnesium alloys can be cited. Aluminum alloys, copper alloys, and magnesium alloys are not particularly limited as long as the thermal conductivity is 100 (W / (m·K)) or more. Below, as specific examples of preferred metal materials, representative material symbols (or their numbers) of metal materials specified in JIS are listed.

[0115] [Materials specified in JIS H4000:2022 (aluminum and aluminum alloy plates and strips), JIS H4001:2006 (hot-dip coated aluminum and aluminum alloy plates and strips), JIS H4040:2015 (aluminum and aluminum alloy bars and wires), and JIS H4140:1988 (aluminum and aluminum alloy forgings)]

[0116] 1085 (=A1085), 1080, 1070, 1060, 1050, 1050A, 1N30, 1N99, 1N90, 1100, 1100A, 1200, 1230A, 2011, 2014, 2014A, 2017, 2017A, 2018, 2117, 2218, 2219, 2024, 2025, 2618, 2N01, 2030, 3102, 3003, 3103, 3203, 3021, 3004, 3004A, 3104, 3204, 3005, 4032, 3105, 5005, 511 0A, 5021, 5041(5N02), 5042, 5050, 5251, 5052, 5154, 5254, 5454, 5754, 5056, 5456, 5082, 5182, 5083, 5086, 6101, 6151, 6005A, 600 5C, 6060, 6061, 6262, 6063, 6181, 6463, 6082, 7003, 7204, 7005, 7020, 7049A, 7010, 7050, 7075, 7N01, 7475, 7178, 8011A, 8021, 8079

[0117] In the embodiment of the present invention, 5052 (A5052) is used as the material of the vial rack.

[0118] [Materials specified in JIS H5202:2010 (aluminum alloy castings) and JIS H5302:2006 (aluminum alloy die castings)]

[0119] AC1B, AC2A, AC2B, AC3A, AC4A, AC4B, AC4C, AC4CH, AC4D, AC5A, AC7A, AC8A, AC8B, AC8C, AC9A, AC9B, Al Cu4Ti, Al Cu4MgTi, Al Cu5MgAg, Al Si11, Al Si12(a), Al Si12(b), Al Si2MgTi, Al Si7Mg, Al Si7Mg0.3, Al Si7Mg0.6, Al Si9Mg, Al Si10Mg, Al Si10Mg(Cu), Al Si5Cu1Mg, Al Si5Cu3, Al Si5Cu3Mg, Al Si5Cu3Mn, Al Si6Cu4, Al Si7Cu2, AlSi7Cu3Mg, Al Si8Cu3, Al Si9Cu1Mg, Al Si12(Cu), Al Si12CuMgNi, Al Si17Cu4Mg, Al Mg3, Al Mg5, Al Mg5(Si), Al Zn5Mg, Al Zn10Si8Mg, ADC1, ADC3, ADC5, ADC6, ADC10, ADC10Z, ADC12, ADC12Z, ADC14, Al Si9, Al Si12(Fe), Al Si10Mg(Fe), Al Si8Cu3, Al Si9Cu3(Fe), Al Si9Cu3(Fe)(Zn), Al Si11Cu2(Fe), Al Si11Cu3(Fe), Al Si12Cu1(Fe), Al Si17Cu4Mg, Al Mg9

[0120] Among the above alloys, AC4B, ADC5, ADC10, ADC10Z, ADC12, ADC12Z, Al Si11Cu3 (Fe), and Al Mg9 have thermal conductivities that vary depending on the material manufacturer, and are materials that may reach 100 W / (m·K). The same is true for the other alloys below, and the list also includes materials that may reach 100 W / (m·K) depending on the material manufacturer.

[0121] [Materials specified in JIS H3100:2018 (sheets and strips of copper and copper alloys), JIS H3110:2018 (sheets and strips of phosphor bronze and nickel silver), JIS H3130:2018 (sheets and strips of beryllium copper, titanium copper, phosphor bronze, nickel-tin copper and nickel silver for springs), JIS H3250:2021 (rods of copper and copper alloys), JIS H3260:2018 (wires of copper and copper alloys), and JIS H3270:2018 (rods and wires of beryllium copper, phosphor bronze and nickel silver)]

[0122] C1011, C1020, C1100, C1201, C1220, C1260, C1441, C1510, C1565, C1700, C1720, C1720, C1751, C1862, C1921 , C1940, C2100, C2200, C2300, C2400, C2600, C2680, C2700, C2720, C2800, C2801, C3501, C3531, C3601, C3602 , C3603, C3604, C3605, C3710, C3712, C3713, C3771, C4250, C4430, C4450, C4621, C4622, C4640, C4641, C5010 , C5015, C5050, C5071, C5071, C6782, C6783, C6801, C6802, C6803, C6804, C6810, C6820, C6870, C6871, C6872

[0123] [Materials specified in JIS H5120:2016 (copper and copper alloy castings) and JIS H5121:2016 (copper alloy continuous castings)]

[0124] CAC101, CAC102, CAC103

[0125] [Materials specified in JIS H4201:2018 (magnesium alloy sheets and strips), JIS H4203:2018 (magnesium alloy bars and wires), and JIS H4205:2020 (magnesium alloy forgings)]

[0126] AZ31B, AZ31C, AZX311, AZ21, ZK30, ZK60, M1, ZM21, ZC71, WZ73, WZ75

[0127] [Materials specified in JIS H5203:2006 (magnesium alloy castings) and JIS H5303:2020 (magnesium alloy die castings)]

[0128] MC6, MC7, MC8, MC9, MC10, MC11, MC14, AM20A

[0129] [Materials specified in JIS H5301:1990 (zinc alloy die casting)]

[0130] ZDC1, ZDC2

[0131] Among the above-mentioned metals with good thermal conductivity, aluminum and aluminum alloys are inexpensive and widely circulated as bulk materials that can be used for cutting, so the vial holder can be manufactured at low cost. In addition, aluminum and aluminum alloys are lightweight and corrosion-resistant, so they are highly practical and preferred materials.

[0132] When a commercially available metal material is used as a metal with good thermal conductivity, the thermal conductivity provided by the manufacturer of the metal material and the thermal conductivity of the metal material specified in JIS corresponding to the metal material can be referred to. When a separate alloy whose thermal conductivity needs to be measured is used, as a method for measuring the thermal conductivity of such an alloy, for example, a laser flash method as a non-steady-state method can be cited. The laser flash method can be implemented using, for example, a commercially available measuring device (referred to as a "laser flash method thermal constant measuring device" or the like) and a test piece appropriately specified by the manufacturer together with the measuring device.

[0133] (Basic shape of the block part of the vial rack)

[0134] The basic shape of the block portion of the vial rack is not particularly limited, and preferably has a three-dimensional shape having a flat surface as the surface for arranging the openings of the holes, and examples thereof include a rectangular parallelepiped, a cube, a cylindrical shape, a polygonal prism shape, and the like. The so-called basic shape in the present invention refers to the overall general shape when it is assumed that there are no holes in the shape of the final block portion (that is, it is assumed that the holes are filled with the material of the block portion), and the locally provided recesses or protrusions, chamfers or arcs of the corners, etc. are ignored. Among them, the rectangular parallelepiped and the cube shape are simple, and are preferred shapes from the viewpoint of preferred compatibility with operating devices such as robots, the viewpoint of high-density configuration of vials, and the viewpoint of configuring multiple vial racks without dead angles. The aforementioned flat surface for arranging the openings of the holes may be not only the upper surface, the side surface, or the lower surface, but also the hole may extend in the lateral direction from the side surface, and further, the hole may extend in the upward direction from the lower surface. In a preferred embodiment in which the vials are held in the holes by gravity and the vials are moved in and out in the vertical direction, as in the conventional vial holder, the flat surface is an upper surface, and one or more holes, preferably a plurality of holes, extend downward from the upper surface toward the inside of the block portion. Even if the vial holder has the upper surface, the orientation of the vial holder when used is not limited, and the vial holder can be used with the upper surface facing horizontally or downwardly.

[0135] When the basic shape of the block portion of the vial rack is a rectangular parallelepiped or a cube, the length of one side thereof is not particularly limited and can be appropriately determined according to the number of vials (the number of holes) and their sizes. However, from the viewpoint of the ease of material acquisition, the ease of manufacturing, the shape and size of the vials to be cooled, the operability of the rack, and the capacity of the program freezer, it is preferably about 5 to 1000 mm, and more preferably about 15 to 500 mm.

[0136] (hole for inserting vial)

[0137] The hole may be a through hole, but is preferably a bag hole from the viewpoint that the block-shaped portion also absorbs latent heat from the lower surface of the vial. The shape of the bottom of the bag hole is preferably similar to the shape of the lower surface of the body portion of the vial. For example, when the basic shape of the outer side of the body portion of the vial is cylindrical, the basic shape of the inner space of the bag hole for inserting the body portion is also cylindrical. The gap between the body portion of the vial and the hole will be described later.

[0138] (Depth of hole)

[0139] The depth of the hole may be such that the entire vial enters the hole, but from the viewpoint of inserting the vial into the hole and taking it out of the hole by grasping the cap, it is preferably such a depth that only the body of the vial enters the hole and the mouth is exposed from the hole. In addition, from the viewpoint of effectively cooling the cell suspension, it is preferably such a depth that at least the liquid surface of the cell suspension can enter the hole in the body of the vial. The height of the liquid surface varies depending on the type and purpose of the cell suspension and the shape of the vial. For example, in the case of a 10R vial specified in ISO 8362-1, it is preferably such a depth that about 85% of the height of the entire container (the dimension from the lower surface to the upper surface of the opening) from the lower surface enters the hole. This allows the cell suspension in the vial to be effectively cooled, and the vial can be easily inserted and removed from the hole by grasping the mouth or the cap.

[0140] (Number of holes)

[0141] The number of holes can be one, and in a preferred mode for mass production, the number of holes is multiple. The number of holes is not particularly limited and can be appropriately selected according to the outer diameter of the vial, the size of the vial rack, etc. As the vial operation is automated and the overall processing capacity of the system increases, the size of the vial rack and the number of holes can also be appropriately increased. The number of holes can be, for example, Figure 3 9 (3 columns and 3 rows) Figure 7 In addition, you can also Fig.19 The number of vial racks may be 78 or more as in the conventional vial rack, and may be 200 to 300 or more.

[0142] (Hole arrangement pattern)

[0143] When a plurality of holes are arranged on the flat upper surface of the block portion, the arrangement pattern of the openings of the holes is not limited, and examples thereof include: Figure 2 (a) As shown in the example, in the upper surface 21a, the center points of the openings of the holes 22 are located at the intersections of the grid-like mesh (the shape of the mesh is rectangular or square) in a matrix arrangement pattern; Figure 2As shown in (b), a fine arrangement pattern in which the center point of the hole opening is located at the intersection of an equilateral triangle mesh (the shape of the mesh is a triangle, especially an equilateral triangle) is a preferred arrangement pattern. The arrangement pattern of the hole opening can also be an arrangement pattern that is interchangeable with the arrangement pattern of the vial insertion port in the vial rack used in the cell freezing system. As long as it is a matrix arrangement pattern, the mechanical structure or control of the robot arm for inserting and removing the vials from the holes can be simplified, and the coordination with the rows and columns of the table when each vial is managed in a table form is good, so it is preferred.

[0144] (The thickness of the wall between adjacent holes)

[0145] In order to conduct the heat absorbed from the main body of the vial to the outer surface of the block portion more quickly, it is preferred that the metal with good thermal conductivity surrounding the hole as the wall is thick enough. Therefore, when a plurality of holes are arranged, the wall between adjacent holes preferably has a sufficient thickness ( Figure 2 (a) Exemplary dimension t1). The thickness of the wall between adjacent holes varies depending on the inner diameter of the hole, but is preferably 1 mm or more, more preferably 2 mm or more, and particularly preferably about 5 to 10 mm. The upper limit of the thickness of the wall is not particularly limited, but from the perspective of excessive thickness leading to waste and making the block portion of the vial rack more compact, the upper limit is preferably about 10 mm.

[0146] (Thickness of the wall between the side of the block and the adjacent hole)

[0147] The thickness of the wall between the side of the block and the adjacent hole ( Figure 2 (a) The illustrated dimension t2) is not particularly limited, but is preferably about 2 to 5 mm from the viewpoint of the mechanical strength of the block portion as a whole and from the viewpoint of making the block portion more compact. In addition, the thickness of the wall (bottom wall) between the bottom surface of the hole and the lower surface of the block portion (the surface on the opposite side of the upper surface) is not particularly limited, but is preferably about 1 to 10 mm, particularly about 1 to 5 mm, for the following reasons.

[0148] For heat conduction from the bottom of the hole to the lower surface of the block portion, and heat conduction from the side of the hole through the wall to the lower surface of the block portion, the speed of the heat conduction will affect the surface temperature of the lower surface of the block portion, so it is ideal that the temperature of the lower surface of the block portion is uniform. If the thickness of the bottom wall is about 1 to 10 mm, the temperature of the lower surface of the block portion can become nearly uniform.

[0149] In addition, if the thickness of the bottom wall is about 1 to 10 mm, the thermal conductivity of the portion between the bottom surface of the hole and the lower surface of the block part in a direction parallel to the lower surface of the block part can become uniform. In addition, the overall mechanical strength of the block part can be improved, and the block part can be made more compact and lightweight.

[0150] (Clearance when inserting vial into hole)

[0151] When the basic shape of the outer side of the body of the vial is cylindrical, the basic shape of the inner space of the hole for inserting the body is also cylindrical. At this time, the difference between the inner diameter of the hole and the outer diameter of the body of the vial (hereinafter, the difference in diameter is also referred to as "the gap e between the hole and the vial") is preferably as small as possible from the viewpoint of heat transfer. However, considering the dimensional error of the vial, the dimensional error of the hole, the increase in the outer diameter when a label (for example, a thickness of about 0.1 mm) is attached to the body of the vial, etc., the gap e between the hole and the vial is preferably about 0.1 to 3 mm, more preferably about 0.1 to 2 mm, further preferably about 0.1 to 1 mm, and particularly preferably about 0.2 to 0.5 mm. In the example product of the present invention, about 0.2 to 0.4 mm is used. By limiting the gap e between the hole and the vial to the above range, the inner surface of the hole and the outer surface (side surface) of the body of the vial are sufficiently close, and the heat transfer between the two is mainly heat conduction and heat radiation, and the cooling unevenness is suppressed, and any vial can be cooled uniformly and quickly. If the gap e between the hole and the vial exceeds 3 mm, the amount of heat conduction from the body surface to the inner surface of the hole may be significantly reduced, although it also depends on the outer diameter of the vial.

[0152] (Spacer given to the hole)

[0153] In a preferred embodiment of the present invention, Figure 3 As shown in (a) as an example, a spacer 22s1 for coaxially positioning the vial 30 in the hole is provided on the inner peripheral surface (side surface) of each hole 22 of the vial holder 20. Figure 3 In the example (a), spacers 22s1 are provided at four locations spaced evenly apart in the circumferential direction of the hole. Figure 3 In the example of (a), the four spacers 22s1 of each hole are integrally connected by the annular plate 22s2 to form a spacer member 22s, but each spacer may be independently embedded or fixed to the inner peripheral surface of the hole by bonding, etc. The spacer member 22s is inserted into each hole to give a spacer to each hole. In the figure, the spacer member 22s is pulled out from the hole 22A for illustration.

[0154] (Isolator method)

[0155] exist Figure 3In the example (a), each spacer 22s1 is a protrusion that continuously extends in the depth direction of the hole like a ridge or a square. Figure 4 As shown in (a), the spacers 22s1 extend from the opening of the hole to the bottom. Each spacer 22s1 may be not only a protrusion extending in a ridgeline shape, but also a single (i.e., island-shaped) protrusion, etc., which protrudes only to a predetermined height from the inner peripheral surface of the hole in such a manner that the main body of the vial holder and the hole are coaxial. By providing the spacers 22s1, the deviation of the vial in the hole can be suppressed, so that the distance between the inner surface of the hole and the outer surface of the vial becomes the same around the entire circumference of the vial body, so that the vials in each hole can be cooled without deviation.

[0156] (Number of Isolators)

[0157] If the spacer 22s1 is a tubular object that covers the entire inner circumference of the hole 22 with a uniform thickness like a bearing sleeve, it may be difficult to insert and remove the vial depending on the material of the spacer, and heat transfer from the vial to the block portion may be hindered. Therefore, the spacer 22s1 is preferably a protrusion that is dispersed at about 3 to 6 locations at equal intervals in the circumferential direction on the inner circumference of the hole. In addition, if the spacer 22s1 is a protrusion, even if the protruding height of the protrusion is too high, and even if the outer diameter of the main body of the vial is too thick due to manufacturing errors, the protrusion will be appropriately collapsed by the inserted vial, so that the main body of the vial can be preferably held coaxially with the hole.

[0158] A plurality of protrusions functioning as spacers may be independently mounted on the inner peripheral surface of the hole. Figure 3 As exemplified in (a), the members may be connected to each other by a ring-shaped connecting member or the like to form a single member (a single spacer member inserted into the hole).

[0159] (Dimensions of protrusion of spacer)

[0160] like Figure 3 As shown in (b), the height h1 of the protrusion from the inner circumferential surface of the hole 22 is preferably smaller than the distance g1 between the two surfaces (half of the gap e between the hole and the vial) generated over the entire circumference when the vial is coaxially inserted into the hole by only about 0.05 to 0.2 mm. For example, when the gap e between the hole and the vial is about 0.1 to 3 mm as described above, the distance g1 between the two surfaces is about e / 2 = 0.05 to 1.5 mm, so the height h1 of the protrusion at this time is preferably about 0.01 to 1.3 mm. The width (circumferential dimension) w1 of the protrusion is not particularly limited, and a preferred dimension is about 1 to 5 mm.

[0161] (Material of spacer)

[0162] The material of the insulator is preferably a material that has little dimensional change due to temperature changes and is not prone to brittle failure at low temperatures. For example, the above-mentioned metals with good thermal conductivity that can be used as materials for small bottle racks, structural metal materials such as steel or stainless steel, and engineering plastics (polyacetal, polyamide, polycarbonate, polyphenylene sulfide, etc.).

[0163] (Relationship between the outer lower surface of the vial and the bottom surface of the hole)

[0164] From the viewpoint of conducting more heat in the vial to the block-shaped portion, it is preferable that the lower surface of the vial and the bottom surface of the hole are in contact with each other. On the other hand, there is a gap e between the side surface of the vial and the hole, and thus, similarly to the gap e on the side surface, there may also be a gap between the lower surface of the vial and the bottom surface of the hole. Therefore, in a preferred embodiment of the present invention, Figure 4 (b) shows an example in which a spacer 22s3 is provided between the lower surface of the body of the vial and the bottom surface of the hole to form a gap g2. The gap g2 can be the same as the distance g1 between the two surfaces generated over the entire circumference when the vial is coaxially inserted into the hole (half of the gap e between the hole and the vial), and can be, for example, about 0.05 to 1.5 mm.

[0165] exist Figure 4 In the example of (b), the spacer 22s3 extends laterally from the lower end of the spacer 22s1 on the side toward the center of the bottom surface of the hole by an appropriate length. Figure 3 The annular plates 22s2 of the spacer member 22s illustrated in (a) are connected in the same annular shape. In addition, the spacer 22s3 may also be a protrusion or a mesh body provided on the bottom surface of the hole. When the spacer 22s3 covers the entire bottom surface of the hole, the heat transfer from the bottom of the vial to the block portion may be hindered depending on the material. In addition, when the metal with good thermal conductivity covers the entire bottom surface, only the hole becomes shallower. Therefore, from the purpose of providing a gap between the lower surface of the vial and the bottom surface of the hole, it is preferred that the bottom surface of the hole is fully exposed.

[0166] (Surface treatment of the inner surface of the hole to improve the emissivity)

[0167] Generally speaking, the amount of heat transferred is (heat conduction > heat radiation), and in particular, in the heat transfer between the object to be cooled and the cold air under the convection of the cold air, heat conduction is dominant and heat radiation can be ignored. However, in a narrow and windless environment such as the gap e between the hole and the vial, the heat conduction becomes small and the influence of heat radiation cannot be ignored.

[0168] Thermal radiation is proportional to the emissivity ε (0-1) of the material surface, and the emissivity ε of an ideal black body is 1. The closer the emissivity ε of the inner surface of the hole is to 1, the more heat released from the vial is absorbed by the inner surface of the hole. Generally speaking, the emissivity ε of the metal surface is less than 0.1, but when the metal surface is colored black, for example, the emissivity ε of the colored surface becomes greater than 0.9, and the amount of heat absorbed from the surface increases by nearly 10 times. In addition, there are cases where the emissivity ε of the surface is made larger by making the surface rougher.

[0169] Therefore, in a preferred embodiment of the present invention, the inner surface (inner peripheral surface and bottom surface) of the hole is subjected to surface treatment for further improving the emissivity. This is preferred because more heat is transferred from the vial to the block portion through the inner surface of the hole.

[0170] Examples of the surface treatment for the inner surface of the hole include aluminum oxide film treatment, coloring such as dyeing, black plating, painting, oxide film formation, deposition film formation, roughening, etc. Roughening may be used in combination with other treatments. Figure 5 An example of coloring the entire inner surface of a hole is shown. Figure 5 (a) shows the state before coloring, Figure 5 (b) shows the state after coloring.

[0171] According to the spectral radiation brightness of a black body based on Planck's law, in the range of room temperature to -80°C, infrared rays with a wavelength of 3 μm or more are mainly radiated from the black body. In order to improve the cooling effect caused by radiation, it is particularly important to increase the emissivity of infrared rays near 3 to 30 μm. As representative surface treatments that are expected to radiate well in this wavelength range, the following can be cited.

[0172] Aluminum oxide film treatment: Anodized film treatment on the surface of aluminum or aluminum alloy. The oxide film (Al2O3) itself shows good infrared emissivity. In addition, the oxide film is porous, so by using colored pigments or dyes, etc., it is expected that the infrared emissivity will be improved. It should be noted that the thermal conductivity of the oxide film (Al2O3) is lower than that of aluminum, so in order to maximize the effects of heat conduction and heat radiation, it is preferred to select the optimal thickness of the oxide film, but even a thin oxide film can be expected to have a sufficient effect.

[0173] Heat-releasing paint: Paints for promoting heat radiation (including materials such as metal oxides, silica, resins, etc.) are commercially available. By applying them to the metal surface of metals with low emissivity, the emissivity can be increased.

[0174] The thickness of the film formed by the surface treatment is not particularly limited. When the film is significantly thick, the original pore diameter may be increased in consideration of the thickness of the film.

[0175] (Air exhaust groove of the hole)

[0176] In the case where the hole is a bag-shaped hole having a bottom surface inside, such as Figure 6 As an example, it is preferred to provide one or more grooves 22a on the inner surface (side surface) of the hole 22 from the opening of the hole to the bottom surface. By providing the grooves 22a, even if the gap e between the hole and the vial is small, when the vial is inserted into the hole 22, the air in the hole is discharged to the outside through the grooves 22a, so that the vial can be inserted into the hole more smoothly. The width of the grooves ( Figure 6 The dimension t10) and the depth of the groove from the inner surface of the hole ( Figure 6 The dimension t20) varies depending on the inner diameter of the hole and is not limited, but is preferably about 1 to 5 mm.

[0177] (The holes are connected to each other through the air exhaust groove)

[0178] Figure 7 , Figure 8 The preferred examples of the vial rack of the present invention are shown. In the examples shown in these figures, the groove provided on the inner peripheral surface of a certain hole (the hole indicated by the symbol 221) is integrally connected with the groove provided in the hole (the hole indicated by the symbol 222) provided in the adjacent position to form a slit 22a1, and the adjacent holes (221, 222) are connected to each other through the slit. With this structure, the space in each hole is connected to the external space on the side of the block portion of the vial rack through the slit. Therefore, even if the overall shape of each hole is a shape that is relatively deep inward, when cleaning the hole, the cleaning liquid injected into the hole can easily flow out through the slit, so that cleaning becomes easy, which is preferred.

[0179] (Attached structure of the vial rack)

[0180] In a preferred embodiment, Figure 7 , Figure 8 As shown, the block portion of the vial rack is provided with a handle 23 for assisting the operation of the vial rack. In addition, the corners of the block portion of the vial rack may be chamfered greatly as shown by reference numeral 21b in order to facilitate the insertion of a dispenser or the like.

[0181] (Manufacturing method of small bottle rack)

[0182] The manufacturing method of the vial rack described above may be not only a subtractive manufacturing method of first preparing a block portion containing a metal having good thermal conductivity and then forming a hole, but also an additive manufacturing method of forming a block portion by casting or forging using a mold, or by stacking a member containing a metal having good thermal conductivity around a portion forming a hole, and any manufacturing method that can form a block portion having a hole may be used. In addition, in the manufacturing of the vial rack, various processing methods may be combined, such as forming a larger shape by casting and improving dimensional accuracy by cutting.

[0183] (Configuration for improving heat exchange performance on the outer surface of the block portion)

[0184] In a preferred embodiment of the present invention, Fig. 9 An example of the structure is schematically shown in the figure, in which a heat sink 40 (41, 42) is provided on the outer surface (side surface in the figure) of the block portion 21 of the vial rack 20. By providing a heat sink on the block portion containing a metal with good thermal conductivity, the efficiency of heat exchange between the block portion and the cold air in the cooling chamber becomes higher, so it is preferred. This vial rack structure with a heat sink provided on the block portion can preferably cool the vials containing the cell suspension using the cooling gas, and is a unique structure of the present invention that has not been available before. The material, structure and other components of the vial rack of the present invention can refer to the components of the vial rack used in the cell freezing system of the present invention.

[0185] The form of the radiator is not particularly limited. The radiator may be a product manufactured for the present invention, or a commercially available heat dissipation product (also referred to as a heat dissipation sheet), or the surface of the block portion may be provided with concave and convex portions to increase the surface area and be used as a radiator. As the material of the radiator, examples include metal materials with high thermal conductivity that are previously known, such as aluminum and aluminum alloys. When the radiator is mounted on the block portion, it is preferred that the radiator be mounted by a method such as screwing, brazing, or welding so that the radiator is in direct contact with the block portion.

[0186] (Configuration for air cooling the lower surface of the vial rack)

[0187] The lower surface of the block portion has a large area, so it is easy to discharge the heat in the block portion. In order to cool the vial rack more effectively by the cold air in the cooling chamber, it is preferred that the cold air flowing in the cooling chamber flows to the lower surface of the block portion and fully contacts it. Therefore, in a preferred embodiment of the present invention, Figure 1In the example shown, the support member 50 is provided to function as a foot, and the block portion 21 of the vial rack 20 is supported in a manner of floating from the arrangement surface by the support member 50, so that the lower surface of the block portion 21 is exposed and can contact the cold air. The support member 50 may be a member different from the vial rack or a frame of a multi-layer rack described later, or may be a member belonging to the cooling chamber, or may be a member provided as a foot on the lower surface of the block portion of the vial rack, or a protrusion on the lower surface of the block portion.

[0188] Fig.10 1 is a perspective view showing an example of a multi-layer rack for arranging a plurality of vial racks in a stacking direction in a cooling chamber. Fig.10 In the example, the multi-layer rack 60 has four layers of frames 61 to 64. The four layers of frames allow four vial racks to be stacked with gaps between them. Each layer of the frame supports the periphery of the lower surface of the block portion of one vial rack. Fig.10 As shown in (a), the lower surface 20b of the block portion of each small bottle rack 20 is exposed at the central opening of each layer frame and can be in contact with cold air.

[0189] The framework approach is not limited to Fig.10 In the example shown in (a), a structure for supporting the lower surface of the block portion of the vial rack at four corners, a structure for supporting at two sides, a structure for holding the side of the vial rack, a structure for supporting with a handle, a structure for providing a hook on the block portion of the vial rack, or the like can be appropriately designed to support the vial rack in a manner that the lower surface of the block portion is fully exposed.

[0190] (Configuration to transfer the heat inside the block portion preferentially to the side)

[0191] exist Fig.10 In the example shown in (a), the vial racks in the multi-layer rack 60 are stacked with sufficient gaps therebetween. If the vial racks are accommodated in a manner that the gaps between the upper and lower vial racks are smaller and more layers are formed, it is difficult for cold air to pass through the gaps between the upper and lower vial racks, and the air cooling effect using the lower surface of the block-shaped portion of each vial rack becomes low. In the present invention, in order to solve this problem, the following structure is proposed, that is, using a heat conduction device such as a heat pipe and a temperature equalizing plate to transfer the heat in each vial rack more quickly to the side of each vial rack, thereby bringing the heat into the cold air from the side. This structure is described below.

[0192] like Fig.11As shown in the exploded assembly diagrams in (a) and (b), in a preferred embodiment of the present invention, a heat conduction device (a temperature equalization plate in the figure) 70 is embedded inside the block portion 21 of the vial rack in such a way that the thermal conductivity between the outer surface (especially the side surface) of the block portion and the periphery of the hole becomes higher. In this structure, compared with a structure of only metal with good thermal conductivity, the heat that enters the block portion through the inner surface of the hole is transferred to the outer surface of the block portion more quickly and / or in greater quantities. As a result, Fig.10 As shown in (b), even if the vial racks are densely stacked in the multi-layer rack 60, the heat inside each vial rack can be more effectively removed by cooling the side of each vial rack using cold air passing through the side of the multi-layer rack 60 (arrows 12 drawn in three dimensions for the purpose of explanation indicate the flow of cold air). Fig.11 As shown, by embedding the heat conduction device inside the block part, the heat around the hole can also be transferred to the lower surface of the block part.

[0193] Examples of the heat transfer device 70 include a heat pipe and a temperature equalizing plate, and these may be used in combination as appropriate.

[0194] A heat pipe is a heat transfer device having a structure in which the pressure inside a long and narrow tube with both ends sealed is reduced to a vacuum and a small amount of working fluid (alternative to Freon, water, etc.) is sealed. The heat applied to one end of the tube is transferred to the other end at a high speed by utilizing the evaporation (gasification at one end), condensation (liquefaction at the other end) and return of the working fluid through the wick of the inner wall due to capillary phenomenon.

[0195] The temperature equalizing plate is a heat transfer device that has a structure in which a thin plate-shaped chamber is depressurized to a vacuum and a small amount of working fluid is sealed in it similarly to a heat pipe, and transfers heat at a high speed based on the same principle as a heat pipe.

[0196] These heat pipes and temperature equalizing plates may be commercially available or may be manufactured for the present invention. The heat conducting device 70 may be mounted on the block portion by screwing, crimping, brazing, embedding in thermally conductive grease, or by close fitting via a heat dissipating sheet.

[0197] exist Fig.11 In the examples (a) and (b), in order to embed the strip-shaped temperature-averaging plate 70 into the block-shaped portion 21 of the vial holder 20, the block-shaped portion 21 is composed of two parts (a main body 211 and a cover 212). The temperature-averaging plate 70 is embedded in a groove 71 formed in the main body 211, and the temperature-averaging plate 70 is covered by the cover 212, forming a Figure 7The small bottle holder shown. With this structure, the thermal conductivity of (between the interior of the block portion 21 (especially around the hole) and the outer surface 211a located at one end side of the temperature equalizing plate 70), (between the interior of the block portion 21 and the outer surface 211b located at the other end side of the temperature equalizing plate 70), (between the interior of the block portion 21 and the upper surface), and (between the interior of the block portion 21 and the lower surface) becomes higher than the thermal conductivity of the metal with good thermal conductivity. The main body 211 and the cover 212 can be fixed to each other by screws, adhesives, welding, brazing, etc.

[0198] (Configuration for transferring heat from the lower surface of the block portion to the side surface)

[0199] In a preferred embodiment of the present invention, Fig.12 (a) schematically shows an example of the structure, in which a heat conduction device 80 is provided to the portion from the lower surface to one side surface of the block portion 21 of the vial rack 20, so that the heat of the lower surface of the block portion 21 is more effectively conducted to the side surface of the block portion. The heat of the lower surface of the block portion refers to the heat existing in the surface layer including the lower surface (i.e., the lower portion of the block portion).

[0200] By providing the heat transfer device 80, such as Fig.10 As shown in (b), even if the vial racks are densely stacked in the multi-layer rack 60, as long as the side surfaces of each vial rack are cooled, the heat inside the block portion of each vial rack can be more efficiently removed than a structure using only metal having good thermal conductivity.

[0201] As the heat transfer device 80, a heat pipe or a temperature equalizing plate can be mentioned, and these can be used in combination as appropriate. These heat pipes and temperature equalizing plates can be commercially available products, or products manufactured for the present invention can be used.

[0202] exist Fig.12 In the example (a), the temperature averaging plate 80 bent into an L shape is provided to cover the lower surface and the side surface of the block portion 21, so that the heat of the lower surface of the block portion 21 is conducted to the side surface. On the side surface of the block portion 21, a heat sink 40 is mounted on the temperature averaging plate 80, and the heat conducted to the side surface is released into the cold air through the heat sink 40.

[0203] In addition, Fig.12 In the example (b), in order to embed the temperature averaging plate 80 bent into an L shape under the surface layer of the lower surface of the block portion 21, the block portion 21 is composed of two parts (a main body 213 and a lower cover 214). The temperature averaging plate 80 is sandwiched between the main body 213 and the lower cover 214 to form a block portion 211. Figure 7The vial holder shown in the figure. On the side of the block portion 21, a heat sink 40 is mounted on the temperature plate 80, and the heat conducted to the side is released into the cold air through the heat sink 40. In addition, in this method, the temperature plate 80 is formed to be exposed at the bottom of the hole and directly absorbs heat from the vial. The main body 213 and the lower cover 214 can be fixed to each other by screws, adhesives, welding, brazing, etc.

[0204] (Temperature Sensor)

[0205] In a preferred embodiment of the present invention, a temperature sensor for measuring the temperature of the block-shaped portion is installed on the block-shaped portion of the vial rack. The temperature sensor is configured to communicate temperature-related data with a control unit and an external device of the gas-cooled freezer when the vial rack is arranged in the cooling chamber of the gas-cooled freezer. Thereby, more precise temperature control can be achieved according to the temperature of the vial rack, and the temperature of the vial rack can be recorded over time. The aforementioned external device can be any device as long as it can communicate temperature-related data with the temperature sensor by wire or wirelessly, and can also be various devices such as a data recording device such as a temperature recorder, an external computer, a communicator and a data recording device connected thereto, and a servo computer on the Internet.

[0206] (Configuration for controlling the temperature of each vial rack individually)

[0207] like Fig.10 As shown in (b), when a plurality of vial racks for accommodating vials are arranged in a multi-layer rack, and the plurality of multi-layer racks are arranged in a wide cooling chamber, the cooling conditions of the vial racks differ depending on the positions in the cooling chamber, and the temperature reduction speed may also differ. In order to solve this problem, the present invention proposes a separate structure for independently heating or cooling each vial rack. This structure is described below.

[0208] like Fig.13 As an example, in a preferred embodiment of the present invention, a heater 90 or a Peltier element 91, preferably both, is provided at the block portion 21 (particularly the lower surface 20b) of each vial rack 20 or at the location for each vial rack in the cooling chamber (the frame 65 of each layer of the multi-layer rack in the figure). One or both of these heaters 90 and Peltier elements 91 are, for example, configured to be connected to the control unit of the gas cooling type refrigerator, and can adjust the temperature of each vial rack separately. Thus, even if there is a deviation in the cooling conditions of the plurality of vial racks arranged in the cooling chamber, each vial rack can be heated or cooled independently, so that the temperature of each vial rack can be finely adjusted while the cooling chamber is cooled as a whole by a fan or the like.

[0209] The configuration in which the temperature of each vial rack can be adjusted individually by a heater or a Peltier element as described above can be realized by combining a vial rack having a block portion made of a metal having good thermal conductivity as a main body and a gas cooling refrigerator.

[0210] These heaters and Peltier elements may be mounted on the lower surface of the block portion of the vial rack, or may be mounted on each layer frame 65 of the multi-layer rack.

[0211] When the vial rack is arranged on the frame 65, the heater and / or Peltier element installed on each layer of the frame 65 of the multi-layer rack contacts the block portion (preferably the lower surface) of the vial rack. Fig.13 As shown, the heater and / or Peltier element preferably covers only a portion of one surface of the block portion, leaving an area that can be contacted by cold air. The electrical wiring for supplying power to the heater and / or Peltier element can be configured so that it can be appropriately connected when the vial rack and the multi-layer rack are arranged in the cooling chamber. The heating and cooling of the heater and / or Peltier element can be implemented according to a predetermined program, or by adjusting the temperature control when the output of the heater and / or Peltier element is adjusted based on the temperature of the vial rack measured by the above-mentioned temperature sensor. The aforementioned program is a data set of cooling conditions (for example, temperature and the time it is maintained, etc.) for obtaining a predetermined temperature change curve. The program can be constructed by a control circuit, and when the control device is a computer, it can also be constructed in the form of computer software.

[0212] The vial rack used in the cell freezing system or the vial rack of the present invention can not only preferably absorb the latent heat when freezing the cell suspension in the vial, but also be useful for suppressing the deviation of the temperature of the vial when transferring multiple vials. For example, in the past, when the cell suspension, etc. were contained in vials for cryopreservation, multiple vials were inserted into a resin vial rack for cryopreservation, which was called a freezing box, etc., and the freezing box was contained in an ultra-low temperature storage container to which liquid nitrogen was added. If the freezing box is taken out from such an ultra-low temperature storage container indoors, the temperature of the freezing box will rise sharply. At this time, the degree of temperature rise of the vial varies greatly depending on the position of the freezing box. Compared with the temperature of the vial near the center, the temperature of the peripheral vials adjacent to the outer peripheral wall (especially the vials at the four corners) becomes higher. In contrast, if the vial rack used in the present invention or the vial rack of the present invention is used as a freezing box, the temperature of each part in the vial rack is uniformed by rapid heat conduction, and the deviation of the temperature of the products in the multiple vials contained in the vial rack is also suppressed. Furthermore, if the vial rack used in the present invention or the vial rack of the present invention is used as a vial carrier, the vials can be cooled by the vial rack, for example, by immersing the lower portion of the vial rack in a tray shallowly filled with liquid nitrogen, so that the inserted vials can be easily maintained at a low temperature. Therefore, even in an operation of transferring the vial rack containing cooled vials from a storage box to a shipping box (an operation outside the cooling chamber), the vials can be easily maintained at a low temperature.

[0213] (Gas Cooling Chiller)

[0214] The "gas cooling type refrigerator" used in the present invention is a refrigerator having a cooling chamber, and uses a low-temperature cooling gas to cool the frozen object placed in the cooling chamber. The gas cooling type refrigerator can be used not only as a device for freezing the frozen object, but also as a refrigerator for refrigerating at a temperature higher than the freezing temperature (for example, 0 to 10°C, etc.) by adjusting the temperature of the cooling gas. The gas cooling type refrigerator may be a product designed and manufactured for the present invention, or a commercially available product.

[0215] When the cell suspension in the vial inserted into the vial rack is frozen by a gas cooling freezer, a low-temperature cooling gas capable of freezing the cell suspension is sent into the cooling chamber. The freezing temperature of the cell suspension varies depending on the composition of the cell suspension, but is generally -60 to -80°C. The temperature of the cooling gas sent into the cooling chamber is preferably sufficiently lower than the freezing temperature. The cooling gas sent into the cooling chamber and its temperature are not particularly limited. Examples include low-temperature air (about -194°C) just after gasification from liquefied air, low-temperature nitrogen (about -196°C) just after gasification from liquid nitrogen, low-temperature carbon dioxide (about -79°C) just after gasification from dry ice or liquefied carbon dioxide, and refrigerants such as Freon (or a substitute for Freon) (about -82°C). In particular, nitrogen obtained from liquid nitrogen is ultra-low temperature and easy to handle, so it is a preferred cooling gas.

[0216] The vaporized low-temperature nitrogen and carbon dioxide can be directly injected into the cooling chamber or mixed with air and injected into the cooling chamber. When air is used as the cooling gas, a cooling device is required to cool the air to a sufficiently low temperature and send it into the cooling chamber.

[0217] exist Fig. 20 In the gas-cooled refrigerator illustrated in the example, as shown by the arrow, it is configured to circulate cold air in the cooling chamber. In the case of stronger cooling, nitrogen gas at -196°C is injected into the cooling chamber, and the gas in the cooling chamber is discharged to the outside from the exhaust port in an amount equivalent to the amount of nitrogen gas flowing in. By finely adjusting the ON / OFF of the injection of the nitrogen gas and stirring the cold air in the cooling chamber, the temperature in the cooling chamber can be preferably controlled. Examples of such gas-cooled refrigerators include CryoMed of ThermoFisher, Kryo of Planar, controlled-rate freezer (CRF) of Biolife Solutions, and CRF of Taiyo Nippon Sanso Corporation. These refrigerators are all program refrigerators described later.

[0218] (Volume of cooling chamber)

[0219] The volume of the cooling chamber of the gas-cooled freezer is not particularly limited and can be appropriately selected from a size that can be placed on a table to a size that can be entered by people, depending on the size of the vial racks to be arranged for mass production and the number of the vial racks.

[0220] (fan)

[0221] The number, flow rate, flow direction, etc. of the fans for spraying cold air into the cooling chamber of the gas cooling refrigerator can utilize those known in the past. A plurality of fans can also be arranged in various directions to evenly deliver cold air to various positions in the cooling chamber.

[0222] (Program Freezer)

[0223] The gas cooling refrigerator is preferably a program refrigerator that can change the cooling capacity according to a pre-set program. The aforementioned program is a data set of cooling conditions (for example, a set of more than one of the temperature of the cooling chamber and the time it is maintained, etc.) for changing the temperature of the cooling chamber according to a predetermined temperature change curve. The program refrigerator is configured to change the temperature of the cooling chamber instantaneously (or with a specified gradient) according to the data set set by the program, and to maintain the specified temperature for only a specified time. The program can be constructed by combining a control circuit with a temperature sensor, a timer, a drive device that changes the output of the cooling source, etc., and when the control device is a computer, it can also be constructed by computer software. If a program refrigerator is used, the temperature rise of the cell suspension caused by latent heat can be more effectively suppressed by changing the pre-set cooling capacity, and the effect of the present invention becomes more significant.

[0224] Most of the cell preservation solutions available on the market are products that solidify at about -5 to -10°C, including supercooled states, so rapid cooling is often performed in this temperature range. Conventional program freezers are configured to be able to set a target temperature in a cooling chamber. Therefore, the operation of cooling a vial containing a cell suspension by a program freezer is performed, for example, according to the steps shown below.

[0225] (Step 1) Precooling of vials in cooling chamber and stabilization of temperature: The temperature in the cooling chamber is set to -10°C, and the period of maintaining at -10°C is set to 20 minutes. Cold air is always circulated. In this environment, each vial is cooled from room temperature with -10°C as the target freezing temperature, and transferred to the next step just before the latent heat is released. By appropriately adjusting the maintenance time at -10°C in step 1 according to the number of vials to be frozen, the amount of liquid, etc., the generation of latent heat in step 2 can be more effectively suppressed.

[0226] (Step 2) Treatment of latent heat: The temperature in the cooling chamber is set to -60°C, and the release of latent heat begins. This strong cooling suppresses the temperature rise caused by latent heat, and all the cell suspensions in the vials are frozen. The period of maintaining -60°C is set to 15 minutes.

[0227] (Step 3) Slow cooling: The temperature in the cooling chamber is set to -50°C. Then, the temperature of the vial is cooled to the set temperature (about -80°C) in such a way that the temperature drop rate of the vial is constant (about -1 to -3 (°C / min)).

[0228] (Step 4) Normal cooling (option): The temperature in the cooling chamber is maintained at -80°C.

[0229] Next, the cell freezing method of the present invention is described.

[0230] The cell freezing method is a method of freezing a cell suspension using the cell freezing system of the present invention. Figure 1 As shown, the cell freezing method includes: a step of preparing a vial rack 20 in which vials 30 are inserted, wherein the vials 30 contain a cell suspension 31 as a freezing object; and a cooling step of cooling the vial rack 20 in which the vials 30 are inserted in the cooling chamber 11 of the gas-cooled refrigerator 10 to cool and freeze the cell suspension 31 as the freezing object.

[0231] In the step of preparing the vial rack to which the vials are inserted, the cell suspension may be first contained in the vial and then the vial may be inserted into the vial rack, or an empty vial may be first inserted into the vial rack and then the cell suspension may be injected into the vial.

[0232] In the cooling process, the gas cooling refrigerator 10 cools the block portion 21 of the vial rack 20 by using cold air at a temperature at which the cell suspension 31 freezes. The cooled block portion 21 effectively absorbs heat from the vials 30 and the cell suspension 31 therein, and the cell suspension 31 is cooled and frozen.

[0233] Example

[0234] (Example 1)

[0235] In this embodiment, a program freezer and a vial rack made of aluminum alloy are used to actually constitute the cell freezing system of the present invention, and the preferred cooling conditions of the program freezer are obtained. It is then confirmed that as long as the cell freezing system of the present invention is used, multiple vials can be preferably cooled at one time even if a gas cooling type freezer is used. The details of the composition of the cell freezing system, vials, cell preservation solution, etc. are as follows.

[0236] (Gas Cooling Chiller)

[0237] Thermo Scientific programmed freezer (CryoMed controlled rate freezer, 7474)

[0238] The program freezer is configured to pre-set the temporal temperature change in the cooling chamber in a programmed manner, and is configured to adjust the injection amount and injection time of the cooling gas (nitrogen at approximately -196°C) flowing into the cooling chamber in such a way that the temporal temperature in the cooling chamber changes according to the program.

[0239] (Small bottle rack)

[0240] The metal having good thermal conductivity as the material of the vial holder is aluminum alloy A5052 specified in JIS H 4000:2014.

[0241] In this embodiment, use Figure 7 The basic shape of the block portion excluding the handle portion is a rectangular parallelepiped (the long side of the upper surface is 122 mm, the short side of the upper surface is 108.5 mm, and the height is 20 mm), which is formed by cutting a block of aluminum material.

[0242] On the upper surface, 16 holes (cylindrical through holes) for inserting vials are arranged in a square matrix of 4 rows and 4 columns. The inner diameter of each hole is 22.3 mm, the depth of each hole is 18 mm, and the center-to-center dimensions of adjacent holes are 30 mm in the long direction and 25.5 mm in the short direction. In this embodiment, no spacers are provided in the holes.

[0243] (Small bottle)

[0244] The container part of the vial is in accordance with ISO 8362-16R and the material is cycloolefin polymer.

[0245] The basic shape of the outer side of the body portion of the vial is cylindrical, and the outer diameter is 22 mm.

[0246] The height from the lower surface of the body portion to the shoulder is 26 mm.

[0247] The cap of the vial was a commercially available product (RayDyLyo CTO 20Φ) comprising a rubber stopper and a plastic cap covering the stopper, and had a built-in rubber stopper conforming to ISO 8362-2.

[0248] (Cell preservation medium)

[0249] The cell preservation solution is an aqueous solution containing dimethyl sulfoxide as a main component, and has a freezing point of about -5° C. 5 mL of the cell preservation solution was injected into each vial, and each vial was sealed with a cap.

[0250] (Structure for placing the small bottle rack in the cooling chamber)

[0251] Insert the vials containing the cell preservation solution into each of the 16 holes set in a vial rack. Prepare 16 sets of vial racks with vials inserted in this way (a total of 256 vials) and set them in the cooling room of the program freezer. Fig.14 As shown in (a), four racks (60a, 60b, 60c, 60d) are used. The structure of each rack is as follows Fig.10 (a) shows a frame structure, and in this embodiment, a 4-layer frame is used. Fig.14 As shown in (a), the four racks are arranged in a 2×2 square matrix pattern, and the 16 sets of vial racks are arranged so that appropriate intervals are provided between the upper and lower racks and between adjacent racks.

[0252] (Shelf)

[0253] like Fig.15 As schematically shown in FIG. 1 , an opening window (through hole) 60h is provided on each shelf plate 60p of each layer where each vial rack is arranged, at a position corresponding to the position directly below the vial. Thus, the lower surface of each vial rack (especially the area corresponding to the position directly below the vial) is exposed to the cold air.

[0254] (Installation of thermocouple on vial and temperature measurement system)

[0255] Through holes were provided in the caps of three vials appropriately selected from the 16 vials inserted into each vial rack so that the temperature of the outer periphery and the center of each vial rack could be measured and the temperature of each part in the cooling chamber could be measured, and a temperature measuring portion of a thermocouple (T thermocouple, 9811 manufactured by Hioki Electric Co., Ltd.) was inserted. Fig.16 The arrangement pattern of three vials provided with thermocouples among the 16 vials in each vial rack arranged on four racks (60a, 60b, 60c, 60d) is shown. Black circles indicate vials provided with thermocouples, and white circles indicate vials not provided with thermocouples. The temperature of the cell preservation solution in the vial is measured over time by the thermocouple and recorded by an external temperature recorder (Memory HiLogger, LR8450 manufactured by Hioki Electric Co., Ltd.). This temperature recorder uses a multi-channel recorder to evaluate the influence of temperature distribution in the process freezer.

[0256] (Overview of Program Optimization)

[0257] An unoptimized temporary program is set, and the recording of temperature data based on the temperature recorder is started. At the same time, the program freezer is started, and the room temperature cooling chamber is cooled according to the temporary program to freeze the cell preservation solution in each vial. Then, the operation of modifying the details of the program based on the temperature change is repeated to obtain an optimized program. The details of the optimization are as follows.

[0258] (Setting value of temporary program)

[0259] Step 1 (cooling from room temperature to freezing temperature):

[0260] Set temperature in the cooling chamber: -10°C (the temperature in the cooling chamber itself drops rapidly from room temperature to the set temperature in about 1 minute, and the temperature in the vial drops under the influence of the temperature in the cooling chamber)

[0261] Maintaining time at -10℃: 20 minutes

[0262] Step 2 (induction of solidification and rapid cooling to suppress temperature rise due to latent heat):

[0263] Set temperature in cooling chamber: -60℃

[0264] Maintaining time at -60℃: 15 minutes

[0265] Step 3 (Recovering from a Cooldown):

[0266] Set temperature in cooling chamber: -50℃

[0267] Time to reach -50℃: 1 minute

[0268] Step 4 (slow cooling for the purpose of inhibiting cell damage associated with freezing):

[0269] The temperature in the cooling chamber was cooled from -50°C to -80°C at a temperature reduction rate of -2°C / min over 15 minutes.

[0270] Step 5 (Normal Cooling):

[0271] Set temperature in cooling chamber: -80℃,

[0272] Maintaining time at -80℃: 30 minutes

[0273] (Procedure Modification)

[0274] After the cooling according to the temporary procedure is completed, the temperature recorder records are analyzed to confirm the temperature change of the cell preservation solution in each vial. Based on the temperature change of the cell preservation solution, the time of latent heat generation (the elapsed time after the start of cooling) and the temperature rise at that time are obtained, and the time of the above step 1 is corrected so that the rapid cooling of the above step 2 is started before the time of latent heat generation (the time when the temperature in the vial reaches 0°C).

[0275] (Further program corrections)

[0276] In addition to using the above correction program, the vial is cooled in the same manner as above, and the target temperature and required time of the rapid cooling in step 2 are optimized so as to suppress latent heat and prevent overcooling. Furthermore, the cooling conditions after the above step 3 are set so that the vial is slowly cooled after the latent heat release is completed. The slow cooling rate is set so that the temperature in the vial is about -1°C / min to -3°C / min. It is ideal to evaluate the optimal slow cooling rate and allowable range after the latent heat is generated separately after the cells are actually frozen.

[0277] The rack arrangement is corrected with reference to the temperature variation of each vial. The vials are arranged away from positions where they cool faster or slower, thereby further suppressing the temperature variation among the vials.

[0278] As described above, it is understood that the cell freezing system of the present invention can preferably freeze the freezing objects in a plurality of vials at a time using a gas cooling type refrigerator.

[0279] (Example 2)

[0280] In this example, the structure of the cell freezing system used in Example 1 was changed to compare a vial rack having a block portion made of metal with good thermal conductivity (the vial rack of Example 1) with a conventional frame-type vial rack (the vial rack of the comparative example).

[0281] (Conventional frame-type vial rack)

[0282] As a conventional vial holder, a Fig.19 (a) A vial rack having a frame structure in which three layers of lattice plates are fixed at intervals by pillars (spacers) at four corners. In this vial rack, cold air enters the vial rack from the side, and the vials are directly cooled by the cold air. The openings of the through holes provided in the lattice plates of the top and second layers are arranged in a 4×4 square matrix, which is the same as the opening arrangement pattern of the vial rack of Example 1. Through holes are also provided in the lattice plates of the bottom layer, but the inner diameter of the opening of the through hole is smaller than the outer diameter of the main body of the vial so that the vial does not fall off. In addition, it is also configured as follows, that is, the temperature measuring part of the thermocouple is inserted into the vial inserted into the previous vial rack in the same arrangement pattern as in Example 1, and the time-dependent temperature of the cell preservation solution contained therein can be recorded by an external temperature recorder.

[0283] (Configuration of the vial rack for comparison)

[0284] Of the total 16 vial racks arranged on the four racks (60a, 60b, 60c, 60d) in the cell freezing system used in Example 1, eight vial racks were replaced with conventional vial racks. Fig.14 As shown in (b), the vial racks 20A of Example 1 and the vial racks 20B of the comparative example are alternately arranged adjacent to each other in the vertical direction and the horizontal direction. All vials stored in the vial racks are the same as those in Example 1. Fig.14 In (b), only the vial rack 20B of the comparative example is hatched for the sake of explanation. The arrangement pattern of the four racks is the same as that of the first embodiment, which is a 2×2 square matrix pattern.

[0285] (Temperature changes in each vial due to rapid freezing)

[0286] In the cooling chamber of the process freezer, Fig.14(b) 4 racks are arranged in the arrangement pattern shown in Figure 1, and rapid cooling is performed. The rapid cooling procedure is as follows. The purpose of this embodiment is to compare the temperature change caused by the generation of latent heat, so the temperature control (temperature rise, slow cooling) after the generation of latent heat is omitted.

[0287] Step 1

[0288] Set temperature in cooling chamber: -20℃

[0289] Maintaining time at -20℃: 5 minutes

[0290] Step 2

[0291] Set temperature in cooling room: -10℃

[0292] Maintaining time at -10℃: 10 minutes

[0293] Step 3

[0294] Set temperature in cooling chamber: -80℃

[0295] Maintaining time at -80℃: 20 minutes

[0296] After the cooling according to the above procedure was completed, the temperature recorder's records were analyzed to confirm the temperature change of the cell preservation solution in each vial.

[0297] Fig.17 Graphs showing typical temperature changes of the cell storage solution in the vial racks of Example 1 and Comparative Example 1. Each graph also shows the temperature change in the cooling chamber. Fig.17 (a) is a graph showing the temperature change of the cell preservation solution in the vials in the vial rack of Example 1, Fig.17 (b) is a graph showing the temperature change of the cell preservation solution in the vial in the conventional vial rack.

[0298] Depend on Fig.17 Comparison of the graphs of (a) and (b) shows that the temperature change in the vials inserted in the vial rack of Example 1 is less rapid than the temperature change in the vials inserted in the vial rack of the comparative example, and the temperature decrease is more stable and closer to a temperature decrease at a constant rate. In addition, from this result, it can be seen that when the cell freezing system of the present invention is used, even if the cooling chamber is simply cooled rapidly, the large heat capacity of the block portion of the vial rack can suppress the rapid temperature increase due to latent heat.

[0299] (Example 3) Cryopreservation of cells

[0300] In this example, the cell freezing system used in Example 1 was used to perform cell cryopreservation.

[0301] The cultured cells (NK cells derived from iPS cells) are recovered by an appropriate method. Next, the obtained cell suspension is washed and concentrated using a cell concentration and washing system (manufactured by Kaneka Corporation).

[0302] Next, the cell storage solution used in Example 1 was added to prepare a cell suspension. The cell density can be any, but is usually 1×10 5 ~1×10 8 cells / mL, more preferably 5×10 5 ~5×10 7 Cells / mL was used as the standard.

[0303] The cell suspension prepared above was aseptically dispensed into the same vials as in Example 1 and sealed.

[0304] Prepare 256 vials containing the cell suspension and place them on 16 vial racks as in Example 1. Fig.14 As shown in (a), the vials were arranged in four racks (4 layers each) and placed in a programmed freezer. Then, the programmed freezer was operated according to a cooling program further optimized based on Example 1 to freeze the cell suspension in the vials.

[0305] After the program is finished, the vials are taken out from the program freezer, placed in a vial box, and stored under liquid nitrogen vapor phase.

[0306] Cells cryopreserved using the cell freezing system of the present invention as described above have their temperature rise due to latent heat suppressed during the freezing stage, which strongly suggests that the survival rate (vitality) of cells during thawing is improved compared to cells cryopreserved using conventional methods.

[0307] Industrial Applicability

[0308] According to the present invention, a large amount of high-quality frozen cells can be stored at one time in the production process of cell medicines. Therefore, the present invention plays an extremely important role in the production of cell medicines.

[0309] Explanation of symbols

[0310] 10 Gas Cooling Chillers

[0311] 11 Cooling Chamber

[0312] 12 Cooling gas (cold air)

[0313] 20 vial rack

[0314] 21A bulk portion containing a metal having good thermal conductivity

[0315] 30 vials

[0316] 31 Cell suspension

[0317] C1 Heat transferred from the bottle rack to the cold air

[0318] This application is based on Japanese Patent Application No. 2022-131339 (filing date: August 19, 2022) filed in Japan, the contents of which are all included in this specification.

Claims

1. A cell freezing system for freezing the cell suspension by cooling one or more vials containing a cell suspension while the vials are inserted into a vial rack, The cell freezing system has: A gas-cooled refrigerator having a cooling chamber, and A small bottle rack arranged in the cooling chamber; The vial holder has a block portion made of metal with good thermal conductivity as a main body, and the block portion has one or more holes for inserting into the body portion of the vial at least to the liquid level of the cell suspension; When in use, the gas-cooled refrigerator cools the vial rack with the vials inserted therein, which is arranged in the cooling chamber, using cooling gas. The cooled vial rack cools the vials and the cell suspension in the vials through the inner surface of the hole of the block portion.

2. The cell freezing system according to claim 1, wherein: The thermal conductivity of the metal having good thermal conductivity is 100 (W / (m·K)) or more.

3. The cell freezing system according to claim 1 or 2, wherein: The metal with good thermal conductivity is aluminum, aluminum alloy, copper, copper alloy, magnesium or magnesium alloy.

4. The cell freezing system according to any one of claims 1 to 3, wherein: The basic shape of the block portion of the vial rack is a three-dimensional shape with a flat upper surface. A plurality of the holes extend from the upper surface toward the interior of the block portion, In the upper surface, openings of the plurality of holes are arranged in a prescribed configuration pattern.

5. The cell freezing system according to claim 4, wherein: The above three-dimensional shape is a cuboid or a cube.

6. The cell freezing system according to any one of claims 1 to 5, wherein: The outer side of the body part of the vial is basically cylindrical, and the inner space of the hole for inserting the body part is basically cylindrical. The difference between the inner diameter of the hole and the outer diameter of the body portion of the vial is 0.1 to 3 mm.

7. The cell freezing system according to any one of claims 1 to 6, wherein: The inner surface of the hole is subjected to surface treatment so as to have a higher emissivity.

8. The cell freezing system according to any one of claims 1 to 7, wherein: The hole is a bag-shaped hole having a bottom surface inside. On the inner surface of the hole, one or more grooves are provided from the opening of the hole to the bottom surface. When the main body of the vial is inserted into the hole, the air in the hole is discharged to the outside through the grooves.

9. The cell freezing system according to claim 8, wherein: The groove provided on the inner peripheral surface of the hole communicates integrally with the groove provided in the hole located at the adjacent position to form one slit, whereby the adjacent holes communicate with each other.

10. The cell freezing system according to any one of claims 1 to 9, wherein: A heat sink is provided on the outer surface of the block-shaped portion so as to further improve the efficiency of heat exchange between the block-shaped portion and the cooling gas in the cooling chamber.

11. The cell freezing system according to any one of claims 1 to 10, wherein: One or both of a heat pipe and a temperature equalizing plate are provided inside the block-shaped portion so that the thermal conductivity between the outer surface of the block-shaped portion and the periphery of the hole is further increased.

12. The cell freezing system according to any one of claims 1 to 11, wherein: The block portion is provided with one or both of a heat pipe and a temperature equalizing plate so that the heat of the lower surface of the block portion can be more efficiently conducted to the side surface of the block portion.

13. The cell freezing system according to any one of claims 1 to 12, wherein: A temperature sensor for measuring the temperature of the block-shaped portion is installed on the block-shaped portion of the above-mentioned vial rack. The temperature sensor is configured to communicate temperature-related data with a control unit of the gas-cooled refrigerator or with an external device when the vial rack is arranged in the cooling chamber of the above-mentioned gas-cooled refrigerator.

14. The cell freezing system according to any one of claims 1 to 13, wherein: The cooling chamber has an indoor space large enough to accommodate a plurality of small bottle racks. One or both of a heater and a Peltier element are provided at the block portion of each vial rack or at the location for each vial rack in the cooling chamber, so that the temperature of each vial rack can be adjusted individually.

15. The cell freezing system according to any one of claims 1 to 14, wherein: The gas cooling type refrigerator is a program refrigerator that can change the cooling capacity according to a pre-set program. The programmed freezer is configured to increase cooling capacity during the period of releasing latent heat so as to suppress a rise in temperature of the cell suspension caused by release of latent heat during freezing of the cell suspension.

16. A vial rack, which is a vial rack used in the cell freezing system according to any one of claims 1 to 15, The main body of the device comprises a block-shaped part made of a metal having good thermal conductivity. The block-shaped part has one or more holes for being inserted into the main body of a vial containing a cell suspension at least to the liquid level of the cell suspension.

17. The vial rack according to claim 16, wherein: A heat sink is provided on the outer surface of the block portion to further improve the efficiency of heat exchange between the block portion and the cooling gas.

18. The vial holder according to claim 16 or 17, wherein: One or both of a heat pipe and a temperature equalizing plate are provided inside the block-shaped portion so that the thermal conductivity between the outer surface of the block-shaped portion and the periphery of the hole is further increased.

19. The vial holder according to any one of claims 16 to 18, wherein: The block portion is provided with one or both of a heat pipe and a temperature equalizing plate so that the heat of the lower surface of the block portion can be more efficiently conducted to the side surface of the block portion.

20. A cell freezing method, which is a cell freezing method using the cell freezing system according to any one of claims 1 to 15, the cell freezing method comprising: A step of preparing a vial rack of the cell freezing system, into which a vial containing a cell suspension to be frozen is inserted; and A cooling step of cooling the vial rack having the vials inserted therein in a cooling chamber of a gas-cooled refrigerator of the cell freezing system to cool and freeze the cell suspension; In the cooling step, the gas-cooled refrigerator uses cooling gas to cool the block portion of the vial rack to a temperature at which the cell suspension is frozen. The cooled block portion cools the vial and the cell suspension in the vial through the inner surface of the hole, thereby freezing the cell suspension.

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