Test tube thawing station

Abstract

Herein is detailed a thawing station for a test tube rack and comprising a suction unit having improved thawing effectiveness over known thawing stations in the art. Also disclosed is a rack holder comprising a plurality of test tube displacers for use with the thawing station.

Description

[0001] TITLE OF INVENTION

[0002] Test Tube Thawing Station

[0003] TECHNICAL FIELD

[0004] The present invention relates to improvements to test tube thawers for low damage thawing of test tubes containing frozen samples .

[0005] BACKGROUND

[0006] In laboratory workplaces, freezing test tubes containing samples, in particular in liquid samples such as in DMSO or water, or samples stored in a liquid, is a commonplace occurrence, both for sample storage as well as for preservation of sample quality over time . However, a prerequisite for the successful storing of frozen samples is the ability to thaw the samples at a later date without sample damage from the thawing.

[0007] In particular in the fields of biological research, correct sample thawing is important in order to avoid sample degradation during thawing from the applied heat to the s amp 1 e .

[0008] Water baths are commonly used, which are useful when a test tube size is appropriate to be substantially submerged in heated water . However, in particular for test tubes conferring to ANSI-standard SLAS x-2004, so-called SBS-format test tubes for being held in racks according to the ANSI-standard, water baths are less practical . For such smaller test tubes (typically not larger than 3-5 cm in height and up to 16mm in diameter) the test tubes (being

[0009] 10318WO00typically made from light weight plastics) will generally float on the water bath and, consequently, are prevented from homogenous thawing from insufficient water immersion. Using a water bath to thaw out such tubes requires a lid to be maintained on the rack during the immersion, to prevent individual tubes from separating from the rack and floating into the water bath. Further, in many cases (e . g. for sterile work) it is highly undesirable to expose the test tubes to water, even if it is only to the outside of the test tubes, for fear of compromising the sterility of the work process or introducing cross contamination between samples . Additionally, the test tubes etc . need to be dried after thawing and also cannot be manipulated by automated handling stations during thawing (such as e . g. capping and decapping) further limiting the use of water bath thawing.

[0010] The present invention concerns a thawing apparatus which permits a complement of test tubes (21 ) held in a standardized test tube rack (20) , preferably an SBS-format test tube rack, to thaw at a rate faster than previously achieved but without compromising e . g. sterility during the thawing process, with the thawing showing enhanced uniformity of the thawed test tubes across the entire complement of test tubes .

[0011] Standardization within the field of test tubes and within the field of standardized racks for holding standardized test tubes has significantly advanced the use of automated capper-decapper devices in the laboratory. Today, the dominating standard for racks for biological and microbiological test tubes are the so-called SBS format racks in accordance with ANSI standard ANSI SLAS x-2004, wherein x = 1, 2, . . 6. Such SBS racks may contain, for example 96 test tubes in a 2-dimensional rack array (22 ) of 8 by 12 ( 8x12 ) test tube

[0012] 10318WO00apertures (23) designed to hold the tubes securely in the rack deck. Also rack arrays (22 ) of 4x6, or 6x8 apertures (23) are in common use . The advantage for automation is that the aperture positions and rack dimensions are predetermined by the standard (e . g. such as defining a predetermined rack frame footprint (203) , a rack foot (204 ) , or defining a protrusion length (1) acceptable in the standard for a test tube to protrude above the rack deck for handling and transport) , and automation equipment can rely on these predetermined positions and dimensions within manufacturing tolerance . Typically, standard SBS racks are manufactured with a closed rack frame (201 ) terminated by a rack deck (202 ) in a bottom open configuration, where in the rack deck (202 ) is arranged the aforementioned 2-dimensional rack array (22 ) of test tube apertures (23 ) . The racks may also be manufactured with a bottom, arranged opposite to the deck. Such closed racks are primarily used for sample transport, but less used in a laboratory setting, as they are more costly. Likewise, it is uncommon for SBS-standardized rack frames (201 ) to contain holes in the rack frames (201 ) or additional holes in the rack deck (202 ) and consequently, when most SBS-racks are viewed along the axis perpendicular to the rack deck (202 ) , a pipe section is revealed that only permits (within manufacturing tolerances) airflow along the axis perpendicular to the rack deck (202 ) . This fact is integrally exploited in the present invention, and the present thawing station is for use with such test tube racks as described above .

[0013] The present invention is detailed in the context of SBS-format standardized racks, however, as will be obvious to the skilled reader, this is only for illustrative purposes as the thawing apparatus of the present invention can be adapted to any type of rack system used in a relevant

[0014] 10318WO00laboratory setting wherein the rack is configured to permit air to flow across the rack along the test tubes therein, i . e . by having a closed rack frame . However, the advantage of the present invention is particularly apparent when used with SBS-standard rack formats, as with little change, the same apparatus can be used with any SBS-format rack.

[0015] In the art, thawing stations for standard format test tube racks are well known, and also the present Applicant manufactures and sells such equipment .

[0016] Figure 1 shows a marketed thawing station ( 1 ) . The shown thawing station is arranged for simultaneous thawing of two SBS-format test tube racks (20) . The thawing station ( 1 ) comprises a cabinet (2 ) defining a cabinet interior (3) where, in the shown example two electric fans (4a, 4b) arranged on each side of a respective angled baffle (5a, 5b) pull in air from the exterior through respective perforations ( 6a) in the cabinet (2 ) and direct the air onto the baffle (5a, 5b) thus channeling the airflow upwards, towards the racks through a grille (7 ) , and wherein at least one integrated heater ( 8a, 8b) further enhances functionality by warming the air as it passes the grille (7 ) , providing a setup similar to a hairdryer . The airflow is low, as blowing too hard from below the test tubes will cause these to blow out of the test tube racks and disperse into the laboratory.

[0017] Surprisingly, as the present inventors have discovered, the setup of the thawing station of the prior art significantly limits the rate of thawing compared to a thawing station of the present invention, when measured under identical conditions . The present inventors have discovered that the underlying cause for the insufficiency of the prior art thawers lie in fact, that the airflow rate actually achieved

[0018] 10318WO00around many (most) of the test tubes in the prior art thawing station ( 1 ) is essentially zero, causing significant thawing time differences between test tubes held in different positions, particularly rim vs . center as shown in Figure 3.

[0019] For this reason, there is herein suggested a thawing apparatus (or thawing station in the parlance of the art) for standard test tube racks, wherein airflow is reversed compared to the thawing stations of the prior art, i . e . the entering air is now being sucked past the test tubes before traversing the suction fans rather than being blown past the test tubes after passage of a blower . Surprisingly, this arrangement of the airflow allows for a much more rapid thawing at lower air temperatures compared to the prior art, even when thawing using room temperature air is compared to using heated air This is particularly beneficial in preventing and avoiding degradation of the samples to be thawed due to the overheating of that part of the samples that is exposed the longest to the hot air . At the same time, the thawing station of the present invention presents significantly improved energy consumption, e . g. by saving energy from not necessarily having to heat the thawing air .

[0020] BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 : Thawing station of the prior art .

[0022] Figure 2 : Thawing station of the present invention.

[0023] Figure 3 : Comparative thawing experiment between the thawing station of the present invention and a thawing station of the prior art .

[0024] Figure 4 : An embodiment of the thawing station of the present invention having a replaceable rack holder .

[0025] Figure 5 : An embodiment of the thawing station of the present invention comprising a temperature sensor .

[0026] 10318WO00Figure 6 : Comparison vacuum turbine vs centrifugal blower . Figure 7 : Thermoregulated hood.

[0027] Figure 8 : Rack mask with hatched lid.

[0028] Figure 9 : Rack mask with pin valve lid.

[0029] Figure 10 : Rack mask experimental setup

[0030] Figure 11 : Rack mask comparison

[0031] It is to be understood that the embodiments shown in the figures are for illustration of the present invention and cannot be construed as limiting the present invention . Unless otherwise indicated, the drawings are intended to be read (e . g. , cross-hatching, arrangement of parts, proportion, degree, etc . ) together with the specification, and are to be considered a portion of the entire written description of this disclosure .

[0032] DETAILED DESCRIPTION

[0033] In accordance with the present invention, there is herein detailed a thawing station as exemplary detailed in Figure 2 .

[0034] The thawing station ( 10) disclosed herein is detailed for use with a standard test tube rack (20, such as particularly preferred an SBS-type standard rack, wherein the rack (20) must comprise a closed rack frame (201 ) and a rack deck (202 ) for holding an upwards defined number of test tubes (21 ) in a corresponding upwards defined number of test tube apertures (23) arranged in a rack deck array (22 ) arranged in the rack deck (202 ) . In principle, there is no limitation to the type of test tube rack that can be used with the present invention, it is merely a question of correctly sizing the parts to each other, e . g. , if the rack frame is an open construction then wrapping it in folio creates the necessary closed rack frame,

[0035] 10318WO00but as explained above , the real advantage of the present invention becomes clear when observed with test tubes suitable for use in a standardi zed rack, such as an SBS-type standard rack .

[0036] Accordingly, there is herein detai led a thawing station ( 10 ) for use with a standardi zed test tube rack ( 20 ) ; the test tube rack ( 20 ) comprising a closed rack frame ( 201 ) defining a rack frame footprint ( 203 ) , and a rack deck ( 202 ) for holding an upwards defined number of test tubes ( 21 ) in a rack deck array ( 22 ) of test tube apertures ( 23 ) arranged in the rack deck ( 202 ) ;

[0037] the thawing station ( 10 ) comprising :

[0038] a thawer unit ( 100 ) comprising a rack holder ( 12 ) arranged for receiving, preferably releasably receiving, and airtight holding the test tube rack ( 20 ) therein, a first air guide ( 13 ) and a suction unit ( 14 ) , the first air guide ( 13 ) arranged for connecting the rack holder ( 12 ) and the suction unit ( 14 ) and guiding an airflow passing the rack holder ( 12 ) to the suction unit ( 14 ) thereby defining a thawer unit airflow direction ( 101 ) ; the rack holder ( 12 ) comprising :

[0039] — a plurality of respective test tube displacers ( 121 ) arranged on the rack holder ( 12 ) ;

[0040] — the plurality of respective test tube displacers ( 121 ) extending, when a test tube rack ( 20 ) is held by the rack holder ( 12 ) , towards the rack deck ( 202 ) , such that a test tube ( 21 ) held in the rack deck ( 202 ) is li fted a distance (d) out of the rack deck ( 202 ) ; and

[0041] — wherein the rack holder ( 12 ) is open for uni form air flow across the rack holder ( 12 ) around each respective test tube displacer ( 121 ) of the plurality of respective test tube displacers ( 121 ) .

[0042] 10318WO00The underlying idea of the above disclosed thawing station ( 10 ) is that rather than relying on slow passage of heated air past the frozen test tubes from below, rapid passage of room temperature air ( or warmer ) from above is able to achieve the thawing much faster and at a lower cost than previously done . However, to achieve this e f fect , the test tubes must be prevented from being pulled or pushed into the test tube rack and thereby blocking the airflow across the thawing station, to which end a thawer unit ( 100 , 300 ) of the invention comprises a rack holder ( 12 ) comprising a plural ity of test tube displacers ( 121 ) , a first air guide ( 13 ) , and a suction unit ( 14 ) , wherein the first air guide ( 13 ) is arranged for connecting the rack holder ( 12 ) and the suction unit ( 14 ) and guiding an airflow generated by the suction unit ( 14 ) past the rack holder ( 12 ) thereby defining a thawer unit airflow direction ( 101 ) . As seen in Figure 2 , together the rack holder ( 12 ) , the first air guide ( 13 ) , and the suction unit ( 14 ) define a first air guide volume ( 131 ) .

[0043] In some embodiments , the thawing station of the invention is as herein further detailed namely : A thawing station ( 10 ) for use with a standardi zed test tube rack ( 20 ) ; the test tube rack ( 20 ) comprising a rack frame ( 201 ) defining a rack frame footprint ( 203 ) , and a rack deck ( 202 ) for holding an upwards defined number of test tubes ( 21 ) in a rack deck array ( 22 ) arranged in the rack deck ( 202 ) ;

[0044] the thawing station ( 10 ) comprising :

[0045] — a cabinet unit ( 11 ) comprising a cabinet ( 110 ) defining a cabinet interior ( 111 ) comprising a first cabinet throughbore ( 112 ) and a second cabinet throughbore ( 113 ) in the cabinet ( 110 ) , wherein a first air guide ( 13 ) is arranged to guide an airflow from the first cabinet throughbore ( 112 ) to a suction unit ( 14 ) , such that when

[0046] 10318WO00the suction unit ( 14 ) is in operation an airflow path is defined such that the airflow can traverse the cabinet ( 110 ) from the first cabinet throughbore ( 112 ) to the second cabinet throughbore ( 113 ) ;

[0047] — a rack holder ( 12 ) configured to be airtight held in or on the first cabinet throughbore ( 112 ) , the rack holder ( 12 ) configured for releasably receiving and airtight holding therein the test tube rack ( 20 ) in an orientation perpendicular to the rack deck ( 202 ) ;

[0048] the rack holder ( 12 ) comprising :

[0049] — a plurality of test tube displacers ( 121 ) equal in number to the upwards defined number of test tubes ( 21 ) in the test tube rack ( 20 ) ;

[0050] — the plurality of test tube displacers ( 121 ) arranged on the rack holder ( 12 ) as a displacer mat ( 122 ) in a displacer mat array ( 123 ) matching the rack deck array ( 22 ) in number and position of the plurality of test tube displacers ( 121 ) ;

[0051] — the plurality of test tube displacers ( 121 ) extending, when a test tube rack ( 20 ) is held by the rack holder ( 12 ) , towards the rack deck ( 202 ) , such that a test tube ( 21 ) held in the rack deck ( 202 ) is li fted a distance (d) out of the rack deck ( 202 ) ; and

[0052] wherein the displacer mat ( 122 ) is open for uni form air flow across the displacer mat ( 122 ) around each displacer ( 121 ) of the plurality of test tube displacers ( 121 ) .

[0053] Due to the particular construction of the rack holder ( 12 ) of the present invention, the position of the suction unit ( 14 ) in a use situation can be above as well as below (with respect to Earth' s gravity field) the rack holder ( 12 ) while

[0054] 10318WO00providing the same outcome of equilibrating test tube samples to the temperature of the air flowing past the test tubes .

[0055] Herein below, the present invention is primarily discussed in the context of the arrangement of the thawer unit ( 100 ) , wherein the rack holder ( 12 ) and the suction unit ( 14 ) are arranged relative to each other such that the first air guide ( 13 ) is arranged for connecting the rack holder ( 12 ) and the suction unit ( 14 ) and guiding an airflow passing the rack holder ( 12 ) to the suction unit ( 14 ) . This arrangement provides for a s impli fied exchange of test tube racks ( 20 ) during operation of the thawing station ( 10 ) of the invention and is therefore preferred for stand-alone laboratory thawing stations . However, for automation the reverse configuration may in many situations be preferable , as will be discussed below .

[0056] In the preferred embodiments of the present invention, and in order to permit an airflow past any test tube held in the test tube rack ( 20 ) and preventing the test tubes from being sucked into hard contact with the rack deck ( 202 ) , the plurality of test tube displacers ( 121 ) normally will be a plurality of respective pins ( 121 ) equal to the upwards defined number of test tubes ( 21 ) of the rack ( 20 ) , wherein the plurality of respective pins ( 121 ) are arranged to form a pin mat ( 122 ) in a pin mat array of the rack holder ( 12 ) matching the rack deck array ( 22 ) arranged in the rack deck ( 202 ) in number and position .

[0057] The thawing station ( 10 ) of the present invention in the preferred embodiment is shown in detail in Figure 2 . Herein the test tube rack ( 20 ) , the thawing station ( 10 ) and the thawer unit ( 100 ) are shown with respect to their relative positions in use . In the embodiments shown in Figure 2 , the

[0058] 10318WO00thawer unit ( 100 ) comprising the rack holder ( 12 ) , the first air guide ( 13 ) and the suction unit ( 14 ) , is operatively arranged in a cabinet ( 11 ) for permitting airflow exiting the suction unit ( 14 ) exit from the cabinet ( 11 ) for thawing frozen samples held in any test tube ( 21 ) contained in the test tube rack ( 20 ) . When arranged as given above , the rack holder ( 12 ) together with the first air guide ( 13 ) and the suction unit ( 14 ) define a first air guide volume ( 131 ) , which by the arrangement becomes exterior to the cabinet ( 11 ) •

[0059] This is merely one of many arrangements of the thawer unit ( 100 ) , the rack holder ( 12 ) , the first air guide ( 13 ) , and the suction unit ( 14 ) in the cabinet ( 11 ) . E . g . the cabinet ( 11 ) can be arranged to engage the first air guide ( 13 ) , or the suction unit ( 14 ) rather than the rack holder ( 12 ) without loss of function, as the primary function of the cabinet ( 11 ) is to serve as a holder for the thawer unit ( 100 ) , such that , when the thawer unit ( 100 ) is installed in the cabinet ( 11 ) , the rack holder ( 12 ) is be arranged with respect to Earth' s gravity field in an essentially level and in an essentially upright position for permitting liquid handling and for avoiding that the test tubes fall out of the test tube rack ( 20 ) during thawing .

[0060] Consequently, the cabinet ( 11 ) does not have to be a closed cabinet ; a frame or a tripod or other such holders are equally useful . Further, an external cabinet , such as e . g . a flow hood etc . (not shown) will often be used with the thawing station ( 10 ) of the present invention, however such an external cabinet does not , in i tself, serve as a holder for the thawer unit ( 100 ) of the invention . In the same manner, one or more air conducts can be attached to the thawer unit ( 100 ) before the rack holder ( 12 ) and / or after the suction

[0061] 10318WO00unit ( 14 ) , i f control of the air quality flowing across the thawer unit ( 100 ) is necessary, however without such air conducts , in themsel ves forming part of the present invention .

[0062] Once the flowing air has passed the test tubes in a uni form manner, the air does not need to flow in controlled paths , which allows freedom for the des ign of the first air guide ( 13 ) . The embodiment shown in Figure 2 , wherein the first air guide ( 13 ) is a funnel , is advantageous as the distance from the rack holder ( 12 ) to the suction unit ( 14 ) can be minimi zed thereby, but this may not necessarily be the only design consideration for a manufactured thawing station ( 10 ) of the invention .

[0063] However, in preferred embodiments of the thawing station ( 10 ) according to any of the embodiments detailed herein, the first air guide ( 13 ) is a funnel as shown in Figure 2 . However, as the first air guide ( 13 ) is not otherwise formally restricted in its construction apart from the requirement of guiding the air from the rack holder ( 12 ) to the suction unit ( 14 ) , consequently the thawer unit ( 100 ) can be arranged with respect to the cabinet ( 11 ) with little restraint , as long as the desired airflow can pass the rack holder ( 12 ) via the first air guide ( 13 ) to the suction unit ( 14 ) and exit the suction unit ( 14 ) , when the suction unit ( 14 ) is on, and the rack holder' s ( 12 ) use position is essentially level and upright .

[0064] As the skilled person will reali ze from the above discussion, the thawing station ( 10 ) of the present invention can function in a minimal configuration wherein the thawing station ( 10 ) consists of the thawer unit ( 100 ) as a handheld device , but commercially an arrangement of the elements in a

[0065] 10318WO00cabinet ( 11 ) or a like such holder represents a signi ficantly better solution, given the time to thaw a rack f illed with frozen samples .

[0066] In the same manner, the skilled person will reali ze that throughout the present disclosure , the term airtight is used with some leeway for less than an absolute airtight connection between two elements that are coupled in an airtight coupling . The underlying reason is that all couplings detailed as airtight serve to guide air in a certain flow pattern necessary for the proper function of the present invention, and accordingly, complete loss of air seal causes loss of function, however some reduction in the degree of air seal does not necessarily lead to a loss of function of the thawing station ( 10 ) of the invention, but rather leads to a reduced user experience , e . g . , by creating longer than necessary thawing times , flow noise , etc .

[0067] In preferred embodiments of the present invention, as shown in Figure 2 , the cabinet ( 11 ) is a partially or fully closed cabinet , such as partially or fully closed box, which is preferred as a commercially optimal embodiment . Preferably, the cabinet ( 11 ) is a box of at least six sides ( l l Oa-d) for ease of manufacture , but here design considerations may guide the skilled person to make other choices .

[0068] In the embodiment shown in Figure 2 , the rack holder ( 12 ) is located such that the rack holder ( 12 ) engages a top side ( 110a ) of the cabinet ( 11 ) in a first cabinet cutout ( 112 ) .

[0069] In a preferred embodiment ( c . f . Figure 2 ) , the top side ( 110a ) of the cabinet ( 11 ) comprises a first cabinet cutout ( 112 ) adapted for releasably receiving and airtight holding the rack holder ( 12 ) therein, and wherein the first air guide

[0070] 10318WO00( 13 ) is airtight circumferentially attached around the first cabinet cutout ( 112 ) . This embodiment is preferred both from a manufacturing and an operational perspective as being easier to assemble and simpler to use . It is within the skills of the person in the art to devise the necessary means for releasably receiving and airtight holding an obj ect in a cutout in a cabinet topside , and such means are considered outside the present invention . For the sake of exempli fication, clamps , gaskets , screws etc . can be mentioned .

[0071] In particularly preferred embodiments of the invention, the rack holder ( 12 ) is exchangeable , as shown in Figure 4 , for permitting a variety of di f ferent pin mat ( 122 ) configurations to be used, thereby providing the thawing station ( 10 ) capacity for a broader range of standard racks , such as 24 , 48 , or 96 aperture SBS-racks . In other embodiments , it is the pin mat ( 122 ) that is exchangeable , while the rack holder ( 12 ) is fixed in the thawer unit ( 100 ) .

[0072] In the embodiment shown in Figure 2 , a second air guide ( 17 ) may connect the suction unit ( 14 ) to a second cabinet cutout ( 113 ) of the cabinet ( 11 ) for allowing air passing the suction unit ( 14 ) exit from the cabinet ( 11 ) . However, i f the cabinet ( 11 ) is closed by a plurality of sides ( l l Oa-d) , the suction unit ( 14 ) in embodiments can be arranged directly in the second cabinet cutout ( 113 ) in a respective cabinet side ( l l Oa-d) of the plurality of cabinet sides ( l l Oa-d) , such that air leaving the suction unit ( 14 ) exits outside of the cabinet ( 11 ) . Normally, however, the arrangement of the thawer unit ( 100 ) within the cabinet ( 11 ) as shown in Figure 2 , wherein the suction unit ( 14 ) is operationally connected to the second cabinet cutout ( 113 ) is preferred both for manufacturing and operational reasons .

[0073] 10318WO00Irrespective of the placement of the suction unit ( 14 ) with respect to the cabinet ( 11 ) , by creating an air flowpath ( 131 , 171 ) through the thawer unit ( 100 ) and across the cabinet ( 11 ) , a cabinet interior ( 111 ) is provided wherein control electronics , in embodiments control electronics comprising a control display ( 16 ) , such as a control display ( 16 ) for displaying a temperature or a temperature di f ference , operatively arranged in a side ( l l Oa-d) of the cabinet ( 11 ) , a power supply ( 19 ) etc . can be installed, thereby creating a thawing station ( 10 ) configured for standalone operation . In preferred embodiments of the thawing station ( 10 ) of the present invention configured for standalone operation, the cabinet is closed by a plurality of sides ( l l Oa-d) , such as being a closed cabinet .

[0074] Making use of thi s , in particularly preferred embodiments of the present invention, the thawing station ( 10 ) of the invention comprises a temperature sensor ( 15 ) arranged inside the first air guide volume ( 131 ) defined by the rack holder ( 12 ) together with the first air guide ( 13 ) and the suction unit ( 14 ) and operatively arranged for providing to a user an indication that test tubes held in the aforementioned rack ( 20 ) are in thermal equilibrium with air at room temperature , preferably providing the aforementioned indication through the temperature sensor ( 15 ) being operatively connected to control electronics comprising a control display ( 16 ) for displaying a temperature or a temperature di f ference .

[0075] It is a particularly preferred benefit of the present thawing stations ( 10 ) of the invention, that with the thawing station of the present invention it is possible to monitor the thawing process externally to the test tubes , as shown in Figure 5 , contrary to the situation for the prior art thawing

[0076] 10318WO00stations, which require temperature probes to be contained inside the test tubes, if the prior art thawing process is to be monitored. The reason for this beneficial effect is that in the present invention, the airflow passing the test tubes will have become cooled by heat exchange with the thawing test tubes, and this reduction in temperature, if measured prior to entering the suction unit ( 14 ) inside the aforementioned first air guide volume ( 131 ) , can be measured up against the entrance temperature (such as room temperature) , such that when the heat-exchanged air measured inside the aforementioned first air guide volume ( 131 ) is essentially equal to room temperature again, the thawing process has come to its completion.

[0077] In the embodiment of the thawing station ( 10) of the present invention comprising a cabinet ( 11 ) as shown in Figures 2 and 4, the cabinet ( 11 ) further preferably may comprise at least three cabinet feet ( 18a-c) , but preferably at least four cabinet feet ( 18a-d) , for creating a free space between the cabinet ( 11 ) and a surface whereupon the cabinet is placed in a use position. Preferably, the cabinet feet ( 18a-d) are height-adjustable ( 181 ) to assure that the thawing station ( 10) , can be positioned in level to prevent misalignment of the rack holder ( 12 ) (and the suction unit ( 14 ) ) during operation.

[0078] In embodiments of the present invention, the second cabinet cutout ( 113) can be, and in some embodiments will be, a plurality of sections, such as a plurality of perforations in the cabinet ( 110) , a grille, or a like arrangement of concentric cutouts, e . g. semi-circles, as is known from the prior art (c . f . Figure 1 ) . As is customary in the art, providing a grille, an arrangement of concentric semicircles, or like arrangements better preserve the structural

[0079] 10318WO00stability of the cabinet ( 110) and the side ( 110b, 110c) of the cabinet comprising the second cabinet section ( 113) than an unstructured section, and consequently is preferred in the present invention.

[0080] In fact (as explained below) , even the first cabinet cutout ( 112 ) is able to perform its function if it is manufactured as a grille (i . e . a plurality of perforations or throughbores ) such as in a thawing station of the prior art, but substituting a single cutout adapted in size to receive the rack holder ( 12 ) therein for a grille or a plurality of perforations lowers the airflow. Consequently, a single cabinet cutout ( 112 ) arranged to receive the rack holder ( 12 ) therein or thereon is the preferred embodiment of the first cabinet section.

[0081] In embodiments of the present invention, preferably the second cabinet cutout ( 113) is manufactured as an assembly of at least two sections, preferably as an assembly of perforations, such as a grille or an arrangement of concentric semi-circles, or a like arrangement .

[0082] Following the above instructions, it is in fact possible to convert a prior art thawing station ( 1 ) into a thawing station ( 10) of the present invention by equipping it with a rack holder ( 12 ) comprising a pin mat ( 112 ) of the present invention positioned directly above its grille (7 ) , reversing the direction of the airflow of the low-capacity fans (4a, 4b) such that air is sucked across the rack holder ( 12 ) rather than being blown across it . However, the thawing station ( 10) of the present invention (see below) can utilize high efficiency suction units ( 14 ) , thereby providing much higher airflows than the low-capacity fans of the prior art, thus

[0083] 10318WO00signi ficantly lowering the overall thawing time by providing higher airflow .

[0084] An essential element of the present invention is the construction of the rack holder ( 12 ) . Accordingly, there is further herein detailed in aspects and embodiments of the present invention a rack holder ( 12 ) for a thawing station ( 10 ) for use with a standardi zed test tube rack ( 20 ) ; the test tube rack ( 20 ) comprising a rack frame ( 201 ) defining a rack frame footprint ( 203 ) , and a rack deck ( 202 ) for holding an upwards defined number of test tubes ( 21 ) in a rack deck array ( 22 ) arranged in the rack deck ( 202 ) ; the rack holder ( 12 ) arranged for receiving, preferably releasably receiving, and airtight holding the test tube rack ( 20 ) therein, the rack holder ( 12 ) comprising :

[0085] — a plurality of respective test tube displacers ( 121 ) arranged on the rack holder ( 12 ) ;

[0086] — the plurality of respective test tube displacers ( 121 ) extending, when a test tube rack ( 20 ) is held by the rack holder ( 12 ) , towards the rack deck ( 202 ) , such that a test tube ( 21 ) held in the rack deck ( 202 ) is li fted a distance ( d) out of the rack deck ( 202 ) ; and

[0087] — wherein the rack holder ( 12 ) is open for uni form air flow across the rack holder ( 12 ) around each respective test tube displacer ( 121 ) of the plurality of respective test tube displacers ( 121 ) .

[0088] Normally, the embodiment of the present rack holder ( 12 ) arranged for releasably receiving and airtight holding the aforementioned standardi zed test tube rack ( 20 ) is the preferred embodiment , as a thawing station, where test tubes must be added to a pre-mounted rack ( 20 ) is less desirable , but this aspect is separate to the functioning of the thawing

[0089] 10318WO00station ( 10) of the present invention. However, in some embodiments the plurality of test tube displacers ( 121 ) can be exchangeable, while the rack holder ( 12 ) is intended for being affixed in a thawing unit ( 100) of the present invention. Once such particularly suitable configuration is when the plurality of test tube displacers ( 121 ) is a plurality of pins ( 121 ) arranged in a pin mat ( 122 ) .

[0090] The rack holder ( 12 ) of the present invention as detailed herein provides an elegant solution to the underlying problem of correctly positioning the test tubes (21 ) in the test tube rack (20) such that air can flow past the test tubes and thawing can occur .

[0091] The distance (d) will depend on a combination of factors, such as the air velocity of the air passing through the thawer unit ( 100) and the surface of the test tubes that are to be exposed to the passing airflow. Since the test tubes for use with SBS-format racks generally are short, i . e . below 5 cm, lifting more than 20% of the test tubes' length causes wobbling of the test tubes in the rack and is generally not desired during use . At the same time, in order to avoid piping noises when the thawing station of the invention is in use, the gap created by the plurality of test tube displacers ( 121 ) cannot be too small either . Additionally, if the distance (d) is too small, the airflow will become reduced, and the thawing time will increase . The distance (d) is typically from 1 mm to 10 mm, preferably from 2 mm to 8 mm, more preferably from 3 mm to 7 mm, or most preferably from 4 mm to 6 mm. In the experiments shown in Figures 3 and 6, a distance (d) of 5 mm was used.

[0092] In the preferred embodiments of the present invention, the plurality of respective test tube displacers ( 121 ) is a

[0093] 10318WO00plurality of respective pins ( 121 ) as detailed in Figure 2 and Figure 4. But while preferred, this configuration is not required. E . g. , an airflow filter of thickness (d) also can serve as the plurality of respective test tube displacers ( 121 ) , e . g. a HEPA filter can be used if sterility is a critical issue in the thawing process . Alternatively, the test tubes can be displaced the required distance (d) by a net comprising a plurality of meshes arranged in the rack holder, as long as air is permitted to flow uniformly along the entire length of the test tubes to be thawed.

[0094] Accordingly, in some embodiments the plurality of test tube displacers ( 121 ) is formed by providing a net having respective individual meshes suitable for holding a test tube without forming an airtight seal .

[0095] And while experiments have shown that the airflow does not have to be perfectly uniform along all test tubes, extensive lack of uniformity creates differences in thawing between the various test tubes contrary to the aims of the present invention .

[0096] In the preferred embodiment of the present invention wherein the plurality of respective test tube displacers ( 121 ) is a plurality of respective pins as shown in Figures 2 and 4, the plurality of respective pins ( 121 ) is arranged on the rack holder ( 12 ) as a pin mat ( 122 ) in a pin mat array ( 123) . Preferably, the plurality of respective pins ( 121 ) is equal in number to the upwards defined number of test tubes (21 ) in the standardized test tube rack (20) ; and matching the rack deck array (22 ) in number and position of the plurality of respective pins ( 121 ) .

[0097] 10318WO00When so arranged, the plurality of respective pins ( 121 ) will extend, when a test tube rack ( 20 ) is held by the rack holder ( 12 ) , towards the rack deck ( 202 ) , such that a respective test tube ( 21 ) held in the rack deck ( 202 ) is li fted the required distance (d) out of the rack deck ( 202 ) by a respective pin .

[0098] In operation, the pin mat ( 122 ) must be open for uni form air flow across the pin mat ( 122 ) around each pin ( 121 ) of the plurality of pins ( 121 ) . This can be achieved e . g . by providing a plurality of holes ( 124 ) in the pin mat ( 122 ) as exemplary shown in Figure 4 , wherein the pin mat ( 122 ) comprises a plurality of holes ( 124 ) arranged around each pin ( 121 ) of the plurality of pins ( 121 ) in the pin mat ( 122 ) for permitting air to flow uni formly across the pin mat ( 122 ) .

[0099] In the presently disclosed pin mats ( 122 ) , the plurality of holes is larger than the plurality of pins ( 121 ) but combined taking up only about 50% of the pin mat surface , thereby providing a structurally stable pin mat ( 122 ) that does not bend under suction, while achieving the goal of an essentially uni form airflow across the pin mat ( 122 ) . There are naturally other ways to arrange a plurality of holes in the pin mats ( 122 ) for use with the present invention, however, in undesired embodiments , airflow is insufficiently uni form across the pin mat ( 122 ) , which entails the risk that thawing becomes inhomogeneous across the frozen test tubes in the rack such as observed in thawing stations of the prior art .

[0100] As thawing is by passing air past the test tubes in a uni form manner to prevent uneven thawing, it is desired that air does not pass into the thawer unit ( 100 ) except through the rack

[0101] 10318WO00deck (202 ) and along the test tubes to be thawed, it is not desired that the airflow takes other paths . For this reason, the rack holder ( 12 ) and the rack (20) must be in airtight connection .

[0102] In order to ensure the necessary airtight seal between the rack holder ( 12 ) and the rack (20) , several means can be applied. However, as normally standardized test tube racks, such as SBS-format racks, have good dimensional stability, it is in many situations sufficient for achieving an effective airtight seal between rack holder ( 12 ) and rack (20) , simply to provide two abutting surfaces, one on the rack frame (202 ) , i . e . its rack frame footprint (203) , and the other on the rack holder ( 12 ) in the form of a flat surface ( 122 ) corresponding in size to the rack' s rack frame footprint (203) . Some loss of air seal can be accepted without influencing the thawing performance, e . g. such as can occur when two abutting surfaces are used, and the rack' s foot has worn to become uneven, but as a loss of the air seal creates unpleasant airflow noises, in an acceptably performing thawing station this should be avoided.

[0103] The flat surface ( 122 ) can, in some embodiments, be arranged in a small recess (not shown) , the recess of depth (a) being slightly larger than the aforementioned rack frame footprint (203) . If the rack holder ( 12 ) comprises such a recess of depth (a) then the pin height must be corrected to (d) - (a) to achieve the overall height of (d) . Alternatively, in other embodiments of the present invention, the rack holder ( 12 ) comprises a gasket for receiving, at least partially, the rack frame (22 ) therein. Other methods of providing effective airtight seals exist and can be employed, however a balance must be struck between cost and performance in a commercially viable thawing station ( 10) .

[0104] 10318WO00It is a particularly important element of the present invention that the first air guide ( 13) and the rack holder ( 12 ) are only required to be coupled sufficiently airtight that air having passed the rack holder ( 12 ) can be guided to the suction unit ( 14 ) , but that the coupling does not have to form a permanently assembled unit . This allows for manufacture, exchange and use of separate rack holders ( 12 ) , wherein each rack holder ( 12 ) is adapted for a different rack array (203) of test tubes (c . f . Figure 4 ) , since this provides for an easy manner of exchange between different rack types and rack dimensions for use with the same cabinet unit ( 11 ) .

[0105] The effectiveness of the present thawing station ( 10) over the prior art apparatus is illustrated in Figure 3, wherein the thawing time of test tubes filled with 0.8 ml water were measured in a comparative experiment, where both thawing stations were operated using room temperature air and an air speed of 0.05 m / s . As can be seen from the figure, thawing using the thawing station ( 10) of the present invention is uniform both for centrally placed test tubes as well as for test tubes at the rim of the test tube rack, and the samples reach room temperature in about 18 minutes, whereas thawing following the prior art is non-uniform with the centrally placed test tubes reaching room temperature after about 30 minutes and the test tubes at the rim only after about 40 minutes, increasing the exposure time to heat of the centrally placed test tubes unnecessarily by 10 minutes .

[0106] The experiments shown in Figure 3 were performed using a vacuum turbine producing a high static pressure of 15 kPa (c . f . Table 1 ) . However, changing the vacuum turbine for a centrifugal blower as the suction unit ( 14 ) , the used

[0107] 10318WO00elements having the below specifications (c . f . Table 1 ) , provided a significant improvement in thawing time as shown in Figure 6, from 11 minutes to 5 minutes for completion of thawing, while significantly improving energy efficiency and lowering machine noise .

[0108] Table 1 : Suction unit specifications

[0109]

[0110] Accordingly, in preferred embodiments of the thawing station ( 10) according to any embodiment detailed herein, the suction unit ( 14 ) is one of either a vacuum turbine or a centrifugal blower, preferably a centrifugal blower, rather than a low-capacity fan. Deciding on a specific suction unit ( 14 ) outside of the above given instructions relate, however, to general optimization of a specific thawing station ( 10) of the present invention and is not further herein detailed.

[0111] Another advantage of using a centrifugal blower rather than a vacuum turbine as the suction unit ( 14 ) is that the airflow now will be directed towards a side ( 110b) of the cabinet ( 110) perpendicular to the side ( 110a) of the cabinet comprising the first cabinet section ( 112 ) rather than towards the bottom ( 110c) of the cabinet ( 110) opposite the side ( 110a) of the cabinet comprising the first cabinet section ( 112 ) , which is preferable for considerations of air exhaust release . Further optimization to energy consumption of the suction unit ( 14 ) and its noise level beyond the preferred use of a centrifugal blower over a vacuum turbine

[0112] 10318WO00is a question of optimization and can be performed by the skilled person using the herein detailed information without inventive skill .

[0113] However, it is a particular advantage of the present invention, that due to the additional airflow capacity obtained through the present configuration, it is possible to split (not shown) the first cabinet cutout ( 112 ) into further respective cutout sections, such as e . g. , two respective cutout sections, three, four, or further respective cutout sections, each respective cutout section in a first configuration open for airflow across the respective cutout section and adapted for releasably receiving and airtight holding one respective rack holder ( 12 ) , but closed for airflow across the respective cutout section in a second configuration. Thereby more than one rack (20) holding frozen test tubes can be thawed at the same time .

[0114] In a further aspect of the present invention and in embodiments thereof, there is further herein detailed a thermoregulated hood (30) (c . f . Figure 7 ) for receiving therein at least one rack holder ( 12 ) according to any of the herein detailed aspects and embodiments, the thermoregulated hood (30) comprising a hood wall (31 ) , at least one thermoregulation element (32 ) , and at least one hood wall cutout (33) arranged in the hood wall (31 ) for creating an airflow hood path (301 ) across the hood (30) for permitting an airflow consecutive passage from the at least one heating element (31 ) and to the rack holder ( 12 ) . In the context of the present invention, the at least one thermoregulation element (32 ) , e . g. a Peltier element, can be a cooling element or a heating element, but generally a heating element is preferred.

[0115] 10318WO00In accordance with the present invention there is further herein detailed a thawing station ( 10) further comprising a thermoregulated hood (30) arranged prior to the rack holder ( 12 ) in the defined thawer unit airflow direction ( 101 ) .

[0116] The advantage of providing a thermoregulated hood (30) according to the herein detailed embodiments is that any sample held in a test tube (21 ) in a test tube rack (20) held in the rack holder ( 12 ) of the present invention can now temperature equilibrate not only with room temperature air, but also with thermoregulated air, whether above or below room temperature . For biological samples the most preferred embodiments involve a heater (32 ) providing hot air at 37 °C, which for many experiments in biology and microbiology is more relevant than experimentation at room temperature .

[0117] In the embodiment shown in Figure 7, the hood wall cutout (33) is a grille, but as discussed above, other solutions for a cutout section are possible in the context of the present invention as long as air is permitted to flow across the at least one thermoregulation element (32 ) and to the rack holder ( 12 ) when the thawing station ( 10) of the present invention is in operation.

[0118] In the embodiment shown in Figure 7, the at least one thermoregulation element (32 ) is an integrated thermoregulation element (32 ) , preferably an integrated heating element (32 ) comprised in the thermoregulated hood (30) in the airflow hood path (301 ) . This embodiment provides a compact solution for the thermoregulated hood (30) and consequently is preferred, however the at least one thermoregulation element (32 ) can also be arranged external

[0119] 10318WO00to the thermoregulated hood (30) as long as it remains arranged in the airflow hood path (301 ) .

[0120] In preferred embodiments of the at least one heating element (32 ) , the at least one heating element (32 ) is a variable temperature heating element, preferably a thermoregulated variable temperature heating element .

[0121] In embodiments of the thermoregulated hood (30) detailed herein, the thermoregulated hood (30) further comprises a temperature sensor (35) arranged in the airflow hood path (301 ) after the at least one thermoregulation element (32 ) but prior to the rack holder ( 12 ) for measuring the temperature of an airflow having passed the at least one thermoregulation element (32 ) prior to reaching the rack holder ( 12 ) . Preferably the temperature sensor (35) is operatively coupled to the heating element (32 ) , when this is a thermoregulated variable temperature heating element such that the temperature output from the heating element (32 ) can adjust to the actual temperature of the airflow for improved temperature control within the test tube samples undergoing temperature equilibration.

[0122] As is evident from the embodiment in Figure 7, the hood wall (31 ) serves as a first air guide ( 13) for the air passing the thermoregulated hood (30) of the present invention. Accordingly, if the thermoregulated hood (30) of the invention further comprises a suction unit ( 14 ) arranged in the airflow hood path (301 ) prior to the rack holder ( 12 ) , whether before or after the thermoregulation element (32 ) , a thawer unit (300) and a thawing station ( 10) of the present invention is obtained. In such a setup, it is preferable to provide an air filter between the suction unit ( 14 ) and the

[0123] 10318WO00rack holder ( 12 ) in the airflow hood path (301 ) to maintain good air quality.

[0124] Such a thawing station ( 10) has advantages for automation, in particular if the hood wall (31 ) is provided with actuation means arranged for moving the hood wall (31 ) relative to the rack holder ( 12 ) , such that a rack holder (21 ) received in the thermoregulated hood (30) can be replaced .

[0125] An underlying, if not explicitly detailed, limitation to the thawing station ( 10) detailed above is that in order for air to flow uniformly around test tubes (21 ) to be thawed and held in a standardized test tube rack (20) suitable for use with the rack holder ( 12 ) of the present invention, is that the test tube rack (20) effectively has to hold essentially its maximum number of test tubes for uniform thawing. It will work even with some or almost all of the test tube apertures (23) in the rack deck array (22 ) not holding a test tube (21 ) , but the efficiency is significantly lowered as air can now flow through uncovered apertures with less flow resistance, rather than around the test tubes held in the rack. This problem can easily be circumvented by placing empty test tubes in the rack to reestablish the desired flow patterns, but if e . g. , a rack holds 10 test tubes out of 96 in an 8x12 SBS-rack, this solution is tedious .

[0126] To overcome the above detailed problem, the present inventors herein propose (c . f . Figures 8 and 9) a rack mask (40) for a standardized test tube rack. Also illustrated in Figures 8 and 9 are thawing stations ( 10) of the present invention further comprising a rack mask (40) as herein detailed.

[0127] 10318WO00In accordance with the present invention and aspects and embodiments thereof, there is herein detailed a rack mask (40) for receiving therein a standardized test tube rack (20) ; the standardized test tube rack (20) comprising a rack deck (202 ) for holding an upwards defined number of test tubes (21 ) in a rack deck array (22 ) of test tube apertures (23) arranged in the rack deck (202 ) and defining an aperture proximity limit circumferential to the rack deck array (22 ) ; the rack mask (40) comprising a closed mask frame (41 ) of height (a) comprising a first opening (411 ) matched in size to enclose the rack deck array (22 ) outside the aperture proximity limit; and a second opening (412 ) oppositely arranged to the first opening (411 ) and terminated by a mask deck (42 ) thereby defining a mask interior (43) adapted for receiving the standardized test tube rack (20) therein; where in the mask deck (42 ) is arranged a mask valve system (400) comprising a plurality of respective mask valves (401 ) arranged in an mask valve array (402 ) corresponding in number and position to the number and position of the rack deck array (22 ) of test tube apertures (23) of the standardized test tube rack (20) ; a respective mask valve (401 ) comprising a respective opening (404 ) in the mask deck (42 ) , and a respective displaceable lid (403) covering the respective opening (404 ) ; and wherein each respective lid (403) is displaceable, when actuated by a test tube (21 ) held in a corresponding respective test tube aperture (23) in a standardized test tube rack (20) received in the mask rack (40) , between a closed position (431 ) and an open position (432 ) , such that an airflow can only pass a respective opening (404 ) when a respective lid (403) is in an open position ( 431 ) .

[0128] In the embodiment shown in Figure 8, each respective opening (404 ) is sized to allow a respective test tube (21 ) held in

[0129] 10318WO00the test tube rack (20) to protrude through the respective opening (404 ) when the rack mask (40) is placed circumferential to the rack deck array (22 ) outside the aperture proximity limit . To achieve this effect, the height (a) of the mask frame is smaller than the protrusion length (1) of the test tube above the rack deck (202 ) .

[0130] The underlying idea herein is that when the rack mask (40) of the invention is placed circumferential to the rack deck array (22 ) outside the aperture proximity limit and aligning the positions of the test tubes, respectively test tube apertures (23) in the test tube rack (20) with the respective lids (403) on the rack mask (40) , then if a respective test tube (21 ) is present in the test tube rack (20) , it will push the respective lid (403) to an open position (432 ) from a closed position (431 ) and respective airflow paths across the rack mask (40) will open only where there is a test tube present, preserving uniformity of the airflow along the test tubes present in the rack (20) . The embodiment shown in Figure 8 corresponds to a rack mask having hinged lids or hatches, i . e . a valve system (400) with a plurality of gates or lids, wherein the test tubes held in the test tube rack (20) directly act on the respective lids .

[0131] The mask frame (41 ) must be a closed mask frame (41 ) as also discussed for the rack frame (201 ) to allow effective airflow across the mask frame (41 ) without substantial loss of airflow. The length by which the first opening (411 ) is oversized compared to the aperture proximity limit in order to allow the mask frame (41 ) to be positioned outside the aperture proximity limit, however varies, depending on particularities of the test tube rack (20) for which the rack mask (40) is intended for use .

[0132] 10318WO00Some test tubes racks (20) have a free rack deck area (25a, 25b) outside the circumference defined by the aperture proximity lime (c . f . Figure 9) , and in such cases the first opening (411 ) only needs to be oversized compared to the aperture proximity limit by a length sufficient to allow placement of the rack mask (40) on top of the free rack deck area (25a, 25b) , c . f . Figure 9. However, placing the rack mask (40) directly on top of the free rack deck area (25a, 25b) can be unstable in use and some rack types do not present such a free rack deck area (25a, 25b) . The embodiment shown in Figure 8 overcomes this problem as the protruding test tubes serve as anchors for the rack mask (40) in use, but for other embodiments of the rack mask (40) this is not an optimal situation.

[0133] Nevertheless, in many situations, particularly where the test tubes in the rack are insufficient to serve as anchors for the rack mask (40) , it is preferable that the height (a) of the mask frame (41 ) is longer than the protrusion length (1) by a length (b) (c . f . Figure 9) , e . g. providing an extension to the mask frame (41 ) in the form of an extension skirt (413) of length (b) , such that the rack mask (40) can fully enclose in the aforementioned mask interior (43) the test tubes (21 ) held in the rack (20) . This allows for better airflow control and a simplified mounting of the rack mask (40) around the rack (20) , which is preferable where automation is intended.

[0134] The embodiment of the rack mask (40) shown in Figure 9 illustrates a preferred embodiment of the rack mask (40) , wherein the respective mask valves (401 ) of the mask valve system (400) are a plurality of respective plungers (403) comprising a lid (433) and an extender (434 ) directed into the mask interior (43) when the rack mask (40) is assembled.

[0135] 10318WO00Thereby the mask valve system (400) effectively becomes a system of plunger valves (or synonymously a system of needle valves) .

[0136] In this embodiment the actuated valve can keep the test tube actuating it inside the mask interior (43) , below the mask deck (42 ) , which is preferable for airflow control .

[0137] No particular limits are placed on the length of the respective pins (434 ) or needles (434 ) used in this embodiment of the rack mask (40) as the additional length that the pins or needles are displaced by the test tubes are a matter more of convenience, i . e . prevention of flow noises or pin wobbling, than function of the rack mask (40) itself (e . g. if the pins are very long, they fall out of the rack mask when actuated, which is inconvenient but does not impede the function of an actuated rack mask (40) ) , and an optimized additional length can be determined by the skilled person with little effort for a particular version of the rack mask (40) and the thawing station ( 10 ) with which it is intended to be used. Nevertheless, in preferred embodiments thereof the mask frame is elongated by a length (b) by provision of an extension skirt (413) . Thereby it is avoided that a respective extender (434 ) is pushed out of a respective mask valve (401 ) , if the protrusion length (1) exceeds the mask frame height (a) .

[0138] As, for reasons of manufacturing, i . e . thermomolding in plastics, most standardized racks (20) have slightly inwardly inclined rack frames (201 ) , this fact can be used to improve the contact of the rack mask (40) of the invention to the test tube rack (20) . The first opening (411 ) must then be matched in size to enclose the rack deck array (22 ) outside the aperture proximity limit such that the first opening is

[0139] 10318WO00larger than the dimensions given by the standard for the particular rack deck (202 ) for which the rack mask (40) is intended. Thereby a degree of gravitational and frictional lock is created between the rack (20) and the rack mask (40) , and a reversible connection, and an airtight seal between rack mask (40) and rack (20) is provided for optimized airflow across the rack mask (40) and rack (20) .

[0140] Consequently, in embodiments of the present rack mask (40) the first opening (411 ) is sized to enclose the rack deck array (22 ) outside the aperture proximity limit such that the first opening is larger than the dimensions given by the standard for the particular rack deck (202 ) for which the rack mask (40) is intended.

[0141] In particular situations, such as for the test tube rack (20) shown in Figure 9, the test tube rack (20) comprises a rack ledge (24 ) circumferentially arranged on the rack frame (201 ) between the rack deck (202 ) and the rack foot (204 ) of the rack frame (201 ) , wherein the ledge is sized to provide a small overlap with the rack frame footprint (203) , such that it becomes easy to stack two racks on top of each other .

[0142] Accordingly, in some of the embodiments of the present rack mask (40) the optional availability of a ledge (24 ) on a rack (20) is exploited by sizing the first opening (411 ) to have a partial size overlap with the rack frame footprint (203) and providing an extension skirt (413) of length (b) for allow the first opening (411 ) to come into contact with the rack ledge (24 ) .

[0143] In embodiments of the present rack mask (40) , the rack mask (40) further comprises a plurality of respective air conduits (441 ) arranged inside the mask interior (44 ) in contact with

[0144] 10318WO00the mask deck ( 42 ) such that each respective air conduit (441 ) is concentrically and circumferential arranged around a respective opening (404 ) comprised in the mask deck (42 ) . Preferably the respective air conduits (441 ) are directly attached to the mask deck around the respective openings (404 ) . In preferred embodiments (c . f . Figure 9) , the respective air conduits (441 ) are formed as an array of walls (442 ) . This latter embodiment allows for easier manufacture and improved placement of the rack mask (40) over a test tube rack (20) .

[0145] In Figure 10 is shown an experimental rack mask (40) of the present invention comprising an array of walls (442 ) in the embodiment detailed in Figure 8 comprising a lidded plurality of valves but no extender . In Figure 11, there is shown the experimental results of thawing a line of 6 out of a 6x8 test tube SBS-rack from a sample temperature of -20°C with (B) and without (A) the rack mask (40) . The temperature feedback without the mask indicates that the thawing process has come to completion after 2 minutes, while the actual temperature is around 20 minutes . With the rack mask (40) , the actual temperature and measured temperature are now (within the accuracy of this preliminary experiment) identical, and the thawing has come to equilibrium after about 12 minutes, showing the effectiveness of the proposed rack mask (40) .

[0146] 10318WO00CLOSING COMMENTS

[0147] Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art in practicing the claimed subj ect matter, from a study of the drawings, the disclosure, and the appended claims .

[0148] The term "comprising" as used in the claims does not exclude other elements or steps . The indefinite article "a" or "an" as used in the claims does not exclude a plurality. A single processor or other unit may fulfill the functions of several means recited in the claims . A reference sign used in a claim shall not be construed as limiting the scope .

[0149] 10318WO00

Claims

36CLAIMS1 . A rack holder ( 12 ) for a thawing station ( 10 ) for use with a standardi zed test tube rack ( 20 ) ; said test tube rack ( 20 ) comprising a rack frame ( 201 ) defining a rack frame footprint ( 203 ) , and a rack deck ( 202 ) for holding an upwards defined number of test tubes ( 21 ) in a rack deck array ( 22 ) arranged in said rack deck ( 202 ) ; said rack holder ( 12 ) configured for releasably receiving and airtight holding therein said test tube rack ( 20 ) in an orientation perpendicular to said rack deck ( 202 ) ; said rack holder ( 12 ) comprising :— a plurality of test tube displacers ( 121 ) equal in number to said upwards defined number of test tubes ( 21 ) in said test tube rack ( 20 ) ;— said plurality of test tube displacers ( 121 ) arranged on said rack holder ( 12 ) as a displacer mat ( 122 ) in a displacer mat array ( 123 ) matching said rack deck array ( 22 ) in number and position of said plurality of test tube displacers ( 121 ) ;— said plurality of test tube displacers ( 121 ) extending, when a test tube rack ( 20 ) is held by said rack holder ( 12 ) , towards said rack deck ( 202 ) , such that a test tube ( 21 ) held in said rack deck ( 202 ) is li fted a distance (d) out of said rack deck ( 202 ) ; and— wherein said displacer mat ( 122 ) is open for uniform air flow across said displacer mat ( 122 ) around each displacer ( 121 ) of said plurality of test tube displacers ( 121 ) .10318WO00372 . A rack holder ( 12 ) according to claim 1 , wherein said plurality of test tube displacers ( 121 ) is formed by providing a net having respective individual meshes suitable for holding a test tube without forming an airtight seal .3 . A rack holder ( 12 ) according to claim 1 , wherein said plurality of test tube displacers ( 121 ) is a plurality of pins ( 121 ) .4 . A rack holder ( 12 ) according to claim 3 , wherein said displacer mat ( 122 ) is a pin mat ( 122 ) arranged in a pin mat array ( 123 ) matching said rack deck array ( 22 ) in number and position of said plurality of pins ( 121 ) ;5 . A rack holder ( 12 ) according to claim 4 , wherein said pin mat ( 122 ) is exchangeable .6 . A rack holder ( 12 ) according to claim 4 or claim 5 , wherein said pin mat ( 122 ) comprises a plurality of holes ( 124 ) arranged around each pin ( 121 ) of said plurality of test tube displacers ( 121 ) in said pin mat ( 122 ) for permitting air to flow uni formly across said pin mat ( 122 ) .7 . A rack holder ( 12 ) according to any of the preceding claims 4 to 6 , whereon a rack holder wall ( 125 ) is circumferentially arranged such that said rack holder wall ( 125 ) and said pin mat ( 122 ) together define a rack confine ( 126 ) matching said defined rack frame footprint ( 203 ) in geometry and si ze within a manufacturing tolerance .10318WO008 . A rack holder ( 12 ) according to any of the preceding claims , wherein said rack holder ( 12 ) is configured to be airtight held in a cabinet throughbore ( 112 ) .9 . A rack holder ( 12 ) according to any preceding claim, wherein said standardi zed test tube rack ( 20 ) is an SBS- format test tube rack .10 . A rack holder ( 12 ) according to any preceding claim arranged for being airtight held, preferably releasably and airtight held, in a first cabinet throughbore ( 112 ) arranged in the cabinet ( 110 ) of a thawing station ( 10 ) according to any of the claims 11 to 24 .11 . A thawing station ( 10 ) for use with a standardi zed test tube rack ( 20 ) ; said test tube rack ( 20 ) comprising a rack frame ( 201 ) defining a rack frame footprint ( 203 ) , and a rack deck ( 202 ) for holding an upwards defined number of test tubes ( 21 ) in a rack deck array ( 22 ) arranged in said rack deck ( 202 ) ;said thawing station ( 10 ) comprising :a cabinet unit ( 11 ) comprising a rack holder ( 12 ) , a first air guide ( 13 ) and a suction unit ( 14 ) , said first air guide ( 13 ) arranged for connecting to said rack holder ( 12 ) and guiding an airflow passing said rack holder ( 12 ) to said suction unit ( 14 ) ;said rack holder ( 12 ) comprising :— a plurality of test tube displacers ( 121 ) arranged on said rack holder ( 12 ) ;— said plurality of test tube displacers ( 121 ) extending, when a test tube rack ( 20 ) is held by said rack holder ( 12 ) , towards said rack deck ( 202 ) , such that a test tube ( 21 ) held in said rack deck ( 202 ) is10318WO00li fted a distance (d) out of said rack deck ( 202 ) ; and— wherein said rack holder ( 12 ) is open for uni form air flow across said rack holder ( 12 ) around each respective displacer ( 121 ) of said plurality of test tube displacers ( 121 ) .12 . A thawing station ( 10 ) for use with a standardi zed test tube rack ( 20 ) ; said test tube rack ( 20 ) comprising a rack frame ( 201 ) defining a rack frame footprint ( 203 ) , and a rack deck ( 202 ) for holding an upwards defined number of test tubes ( 21 ) in a rack deck array ( 22 ) arranged in said rack deck ( 202 ) ;said thawing station ( 10 ) comprising :— a cabinet unit ( 11 ) comprising a cabinet ( 110 ) defining a cabinet interior ( 111 ) comprising a first cabinet throughbore ( 112 ) and a second cabinet throughbore ( 113 ) in said cabinet ( 110 ) , wherein a first air guide ( 13 ) is arranged to guide an airflow from said first cabinet throughbore ( 112 ) to a suction unit ( 14 ) , such that when said suction unit ( 14 ) is in operation an airflow path is defined such that said airflow can traverse said cabinet ( 110 ) from said first cabinet throughbore ( 112 ) to said second cabinet throughbore ( 113 ) ;— a rack holder ( 12 ) configured to be airtight held in or on said first cabinet throughbore ( 112 ) , said rack holder ( 12 ) configured for releasably receiving and airtight holding therein said test tube rack ( 20 ) in an orientation perpendicular to said rack deck ( 202 ) ; said rack holder ( 12 ) comprising :10318WO00— a plurality of test tube displacers ( 121 ) equal in number to said upwards defined number of test tubes ( 21 ) in said test tube rack ( 20 ) ;— said plurality of test tube displacers ( 121 ) arranged on said rack holder ( 12 ) as a displacer mat ( 122 ) in a displacer mat array ( 123 ) matching said rack deck array ( 22 ) in number and position of said plurality of test tube displacers ( 121 ) ;— said plurality of test tube displacers ( 121 ) extending, when a test tube rack ( 20 ) is held by said rack holder ( 12 ) , towards said rack deck ( 202 ) , such that a test tube ( 21 ) held in said rack deck ( 202 ) is li fted a distance (d) out of said rack deck ( 202 ) ; and— wherein said displacer mat ( 122 ) is open for uniform air flow across said displacer mat ( 122 ) around each displacer ( 121 ) of said plurality of test tube displacers ( 121 ) .13 . A thawing station ( 10 ) according to either claim 11 or claim 12 , wherein said rack holder ( 12 ) is according to any of the claims 1 to 10 .14 . A thawing station ( 10 ) according to any of the preceding claims 11 to 13 , arranged for releasably and airtight holding said rack holder ( 12 ) in said first cabinet throughbore ( 112 ) .15 . A thawing station ( 10 ) according to any of the preceding claims 11 to 14 , further comprising a temperature sensor ( 15 ) operatively arranged in said cabinet interior ( 111 ) after said suction unit ( 14 ) for measuring an air10318WO0041temperature of said airflow traversing said cabinet ( 110) .

16. A thawing station ( 10) according to claim 15, wherein said temperature sensor ( 15) is operatively connected to a display ( 16) for providing to a user an indication that test tubes held in said test tube rack (20) are in thermal equilibrium with air at a predefined temperature, preferably room temperature .

17. A thawing station ( 10) according to any of the preceding claims 11 to 16, further comprising a second air guide ( 17 ) for guiding said airflow traversing said cabinet ( 110) from said suction unit ( 14 ) to said second cabinet throughbore ( 113) .

18. A thawing station ( 10) according to any of the preceding claims 11 to 17, wherein said first air guide ( 13) is a funnel .

19. A thawing station ( 10) according to any of the preceding claims 11 to 18, wherein said second cabinet throughbore ( 113) is manufactured as an assembly of at least two throughbores, preferably as an assembly of perforations .

20. A thawing station ( 10) according to any of the preceding claims 11 to 19, wherein said suction unit ( 14 ) is one of either a vacuum turbine or a centrifugal blower, preferably a centrifugal blower .

21. A thawing station ( 10) to any of the preceding claims 11 to 20, wherein said first cabinet throughbore ( 112 ) is split into at least two separate cabinet throughbores , each separate cabinet throughbore adapted for releasably10318WO0042receiving and airtight holding one respective rack holder ( 12 ) according to any of the claims 1 to 10.

22. A thawing station ( 10) according to any of the preceding claims 11 to 21, further comprising a thermoregulated hood (30) according to any of the claims 23 to 25.

23. A thermoregulated hood (30) for receiving at least one rack holder ( 12 ) according to any of the claims 12 to 18 therein, comprising a hood wall (31 ) , at least one integrated heating element (32 ) , and at least one throughbore (33) in said hood wall (31 ) thereby creating an airflow path (301 ) across said hood (30) for permitting an airflow consecutive passage of said at least one integrated heating element (31 ) and said rack holder ( 12 ) .

24. A thermoregulated hood (30) according to claim 23, wherein said at least one integrated heating element (31 ) is a variable temperature heating element, preferably a thermoregulated variable temperature heating element .

25. A thermoregulated hood (30) according to claim 23 or claim 24, wherein a panel (311 ) in said hood wall (31 ) permits insertion and removal of said rack holder ( 12 ) into and from said thermoregulated hood (30) .10318WO00

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