Balancing weights

Abstract

Balancing body (1) for weight compensation on a rotor (70) of a centrifuge (60), wherein the balancing body (1) is designed separately from the rotor (70) and for receiving at a receiving place (72) for carriers (73) for reaction vessel units (50) on the rotor (70), wherein the balancing body (1) is non-magnetic or non-magnetic.

Description

[0001] The present invention relates to a balancing body for weight compensation on the rotor of a centrifuge, designed to be received in a receiving location for carriers for reaction vessel units, as well as to a system with a carrier, in particular a magnetic carrier, and the balancing body.

[0002] Reaction vessel units such as microtiter plates are used for laboratory work or experiments. Reaction vessel units have reaction vessels arranged in a grid, which are used to hold samples for conducting chemical, biological, microbiological and other experiments. A target substance such as cells, organoids or spheroids as a cell complex, macromolecules such as DNA strands or DNA sequences can be suspended in the reaction vessel in a liquid such as a nutrient medium. It is often desirable to remove the liquid from time to time to replace it with fresh liquid or to allow separate access to the target substance. Removing the liquid is also referred to as "washing". For this purpose, a centrifuge with a rotor is often used. This rotor has two diametrically opposed receiving spaces, each of which holds a reaction vessel unit.More precisely, the receiving locations of the rotor are each designed to accommodate a carrier for a reaction vessel unit with a reaction vessel unit arranged thereon. The carriers are each shaped to fit receiving elements on the rotor of the centrifuge on the one hand, and to accommodate a reaction vessel unit on the other. They can also be understood as adapters between the centrifuge (rotor) and the reaction vessel unit. US 2021 / 138485 A1 and US 11,117,142 B2, for example, disclose centrifuging devices for washing reaction vessel units. With these centrifuging devices, the reaction vessels are arranged with their openings facing away from the axis of rotation, so that the liquid contained in the reaction vessels is ejected during centrifugation. Often, only one receiving location on the rotor is occupied by a carrier with a reaction vessel unit (hereinafter also referred to as the "active carrier").In order to avoid imbalances, an empty carrier or a carrier with an empty reaction vessel unit (hereinafter also referred to as “compensating carrier”) is often arranged on the other receiving location.

[0003] Weight compensation is particularly important when the carrier has a high mass due to special design features. This is the case, for example, with a magnetic carrier as shown in WO 2015 / 018878 A2. In such magnetic carriers, magnets are arranged on the carrier (often cast or similar) in order to exert a magnetic force on magnetic particles in the reaction vessels of the reaction vessel unit. Such magnetic carriers are comparatively heavy and generate a correspondingly high imbalance when rotating. Using an empty magnetic carrier as a compensation carrier can be uneconomical because the magnetic carriers are comparatively expensive. Instead, special balancing bodies are used which, in relation to receiving elements on the rotor which are used to receive a carrier, may bewith a reaction vessel unit arranged thereon, have a complementary structure, and have a weight corresponding to the high weight of the magnet carrier. Although this is not mandatory, such balancing bodies can also be designed as a carrier for an empty reaction vessel unit, which corresponds to the reaction vessel unit on the active magnet carrier.

[0004] An object of the invention is to provide a balancing body for arrangement on a rotor of a centrifuge for balancing a weight of a carrier, in particular a magnetic carrier, arranged diametrically opposite the balancing carrier, for a reaction vessel unit, in particular during rotation of the rotor, with which a safe handling of the balancing body and the carrier is enabled.

[0005] A further object of the invention is to provide a balancing body for arrangement on a rotor of a centrifuge for balancing a weight of a carrier, in particular a magnetic carrier, arranged diametrically opposite the balancing body for a reaction vessel unit, with which a more uniform running of the centrifuge is enabled.

[0006] A further object of the invention is to provide a system with a balancing body and a carrier, in particular a magnetic carrier, for a reaction vessel unit, which are designed to match each other, which is safe to handle and enables a smooth running of a centrifuge when arranged on the rotor of the centrifuge.

[0007] One or more of the objects of the invention are achieved, at least in part, by the features of the independent claims. Preferred embodiments and advantageous developments are specified in the subclaims.

[0008] The inventors have discovered that when magnetic carriers are used as balancing bodies, it can happen during handling that the balancing bodies adhere to the magnetic carrier. This can also occur with balancing bodies that have an insert made of steel with a ferritic structure or iron to increase mass. These materials offer advantages in terms of specific weight, availability, and cost. However, these materials are magnetic, so it can happen that a balancing body is magnetically attracted to a magnetic carrier during handling and the balancing body adheres to the magnetic carrier. Due to the high magnetic forces, it is often not possible to separate the adhering balancing body from the magnetic carrier without causing damage, which can lead to total failure of the magnetic carrier and / or the balancing body.Since such magnetic carriers are expensive to produce, simply due to the cost of the usually high-quality magnets, the economic damage in such a case is considerable.

[0009] The invention is therefore based on one aspect of the consideration of avoiding magnetic attraction between the magnetic carrier and the balancing body. This is achieved according to the invention by a balancing body for weight compensation on a centrifuge rotor, which balancing body is designed separately from the rotor and for receiving a receiving location for carriers for reaction vessel units on the rotor, and which is non-magnetic or amagnetic. Such a design of the balancing body ensures that the balancing body and the carrier do not stick to one another, even if the carrier is a magnetic carrier. Therefore, the invention in this aspect enables safe handling of the balancing body and the carrier.

[0010] In embodiments, it is provided that the balancing body has at least one trim weight, wherein the trim weight is made of a non-magnetizable material, which preferably has a density of at least 6 g / cm 3 , in particular metal, preferably non-magnetic steel, lead, copper, brass or an alloy thereof, as a monolithic body or as a polymer-bonded powder, and / or ceramic. A trim weight is understood to be a body that can be arranged or is arranged on the balancing body or a base body thereof in order to increase its mass. The location of the trim weight can be used to specifically influence the moment of inertia of the balancing body. Multiple trim weights can also be provided on the balancing body.

[0011] In embodiments, it is provided that the balancing body has a base body made of plastic, which integrally comprises the trim weight or by which the trim weight is received, wherein the base body is produced in particular by an additive process and / or a casting process and / or a machining process, for example milling. A base body is understood to be a frame or the like that defines an outer contour of the balancing body, while the mass and / or the moment of inertia of the balancing body is changed via the trim weight. One or more receiving areas can be provided on the base body to receive the trim weight. The outer contour of the balancing body can therefore form the interface to a receiving location on a rotor of a centrifuge, regardless of the mass distribution significantly determined by the trim weights.

[0012] The trim weight can be arranged on the base body, preferably in an interchangeable manner. An interchangeable holder can enable variable adaptation of the balancing body to different supports. In particular, supports for reaction vessel units with different numbers of reaction vessels can be adapted. Interchangeability can be achieved, for example, by screwing, clipping, captively inserting, locking, frictional or form-fitting, or any other suitable connection method. Alternatively, the trim weight can also be permanently attached to the base body, for example, cast, glued, or additively formed or integrated with it. In these cases, the balancing body can be adapted to a specific type of support, with or without a reaction vessel unit.Each balancing body can be identified and, if necessary, individualized by an identifier, such as a shaped feature, an imprint or sticker with a code, in particular a barcode or QR code, an imprint or embossing, an RFID tag, or other features. By providing several specialized balancing bodies, in particular with an identifier as described above, handling during operation can be simplified, accelerated, and made safer. If the base body is always the same for each configuration or a multitude of configurations of trimming bodies, a multitude of balancing bodies can be produced in a modular manner by appropriately selecting the trimming weight(s). This considerably simplifies the production of the balancing body for different applications.

[0013] In some embodiments, the trim weight is cuboid-shaped and preferably made from a rod-shaped semi-finished product. This allows for easy storage of semi-finished products and the trim weights to be manufactured in a simple and standardized manner by cutting to length and / or other processing methods.

[0014] In embodiments, the base body is provided with a receiving area for trim weights. The receiving area can be adapted to a specific geometry of trim weights. This creates even more options for configuring the balancing body. The receiving area can have one or more slot- or groove-shaped recesses, in particular depressions and / or openings, preferably on or in a base wall. The plurality of recesses can preferably extend parallel to one another. Furthermore, the plurality of recesses can be arranged symmetrically about a plane of symmetry of the base body. The plane of symmetry is preferably a plane extending vertically in the longitudinal direction. The plane of symmetry contains a rotor axis of a centrifuge when the balancing body is received on the rotor of the centrifuge.

[0015] Furthermore, trim weights of different lengths or different thicknesses or different widths or different masses can be accommodated in the receiving area, in particular in each of several recesses.

[0016] It may also be preferred if the balancing body has a mass of at least 50 g, or at least 100 g, or at least 150 g, or at least 200 g, and / or of at most 650 g, or at most 550 g, or at most 450 g, or at most 350 g. This allows the balancing body to be adapted to the mass of a support for reaction vessel units, in particular magnetic supports with magnets that have a comparatively large mass, with or without a reaction vessel unit.

[0017] Furthermore, the inventors discovered that using a balancing body to counterbalance the weight of a magnetic carrier can result in uneven rotor running, even if the mass of the balancing body matches the mass of the carrier. This leads to the assumption that rotor imbalance cannot be completely eliminated even by adjusting the mass of the balancing body.

[0018] According to a further aspect, the invention is based on the consideration that the remaining imbalance of the rotor can be avoided by a suitably selected weight distribution within the balancing body.

[0019] A further aspect of the invention relates to a system comprising a support, in particular a magnetic support, for reaction vessel units and a balancing body as described above, wherein the balancing body and the support have an identical reference contour, wherein the balancing body is adapted to the support with regard to the center of gravity and / or mass moment of inertia and / or local weighted area moments of inertia with respect to a rotational axis of the rotor. In other words, the center of gravity and / or mass moment of inertia and / or local weighted area moments of inertia of the balancing body is / are adapted to the center of gravity and / or mass moment of inertia and / or local weighted area moments of inertia of the support, with or without the reaction vessel unit, in each case relative to the arrangement on the rotor of the centrifuge. This makes it possible to avoid imbalances when the rotor rotates with the support and balancing body.

[0020] It can be advantageous if the balancing body has the same mass as the carrier.

[0021] Furthermore, it is preferable for the balancing body to have the same mass moment of inertia and / or the same local weighted areal moments of inertia in each cross-section with respect to the / a rotational axis of the rotor as the carrier. In this case, the balancing body can, in particular, have a mass distribution such that, for a weight corresponding to a corresponding carrier, in particular a magnetic carrier, which can be accommodated in the receiving location of the rotor, a mass moment of inertia and / or the same local weighted areal moments of inertia with respect to a rotational axis of the rotor are / are created that correspond to that of the corresponding carrier with respect to the rotational axis of the rotor.

[0022] In particular, it can be provided that the balancing body has the same center of gravity position with respect to the reference contour as the magnet carrier, wherein the center of gravity of the balancing body is in particular at the same height as the center of gravity of the carrier.

[0023] The reference contour is preferably a contour that is complementary to a receiving contour for receiving the carrier on the rotor. In particular, the reference contour can be an outline or a surface of a bottom wall of the carrier and the balancing body.

[0024] The invention shows its advantages in particular when the carrier is a magnetic carrier, wherein the magnetic carrier has a receiving area for receiving a reaction vessel unit and a magnet arrangement with magnets arranged in a matrix.

[0025] A magnet carrier has a magnet arrangement of magnets designed to exert a magnetic effect on components contained in reaction vessels of a reaction vessel unit arranged on the magnet carrier. Each reaction vessel of the reaction vessel unit can be assigned a magnet or a group of several magnets arranged beneath the reaction vessel. The magnets can be arranged in a matrix. Furthermore, magnetic force increasing means can be provided, designed to increase the magnetic effect of the magnets of the magnet arrangement located at the edges of the matrix. The magnetic force increasing means can comprise an auxiliary magnet arrangement of auxiliary magnets arranged outside the magnet arrangement. The auxiliary magnets can each be arranged adjacent to an edge-side magnet of the magnet arrangement.Such magnetic carriers are the subject of another utility model filed on the same day, the disclosure of which with regard to the arrangement of the auxiliary magnets is fully incorporated by reference.

[0026] Selected embodiments of the present invention are described in detail below with reference to the accompanying drawings. They show: Fig. 1A shows a balancing body according to an embodiment of the invention in a perspective view obliquely from above; Fig. 1B the balancing body in a bottom view; Fig. 2 the balancing body in a plan view; Fig. 3 the balancing body in a cross-sectional view along a section plane III-III in Fig. 2; Fig. 4A the balancing body in a bottom view; Fig. 4B the balancing body in a modification in a bottom view in a modification; Fig. 5A shows an exemplary reaction vessel unit for use on the magnetic carrier of Fig. 1 in a plan view; Fig. 5B the reaction vessel unit from Fig. 5A in a sectional side view; Fig. 6 a centrifuge with a reaction vessel unit arranged outside a rotor chamber on a carrier; Fig. 7A shows an arrangement of the balancing body and a carrier on a rotor of a centrifuge in a perspective view; Fig. 7B the arrangement from Fig. 7A in a cross-sectional view. Fig. 8 a carrier with a magnet arrangement for a reaction vessel unit in a cross-sectional view analogous to the view in Fig. 3.

[0027] A balancing body 1 according to the invention is described below with reference to Fig. 1A to 4B and in its application by reference to the Fig. 7A, Fig. 7B. The balancing body 1 serves as a counterweight or balancing weight for a rotor 70 (cf. Fig. 7A, Fig. 7B) a centrifuge 60 (cf. Fig. 6) arranged support 73 (cf. Fig. 6, Fig. 7A, Fig. 7B) with a reaction vessel unit 50 (cf. Fig. 5A, Fig. 5B).

[0028] The balancing body 1 comprises a base body 2 with a bottom wall 3 and a side wall 4, which can also form a support surface for a reaction vessel unit 50. The bottom wall 3 and the side wall 4 define a receiving area 6 for a reaction vessel unit 50, similar to a conventional support. Wall recesses 5 are formed in the side wall 4, which allow or facilitate gripping a reaction vessel unit 50 received by the balancing body 1.

[0029] To facilitate assignment, directions with respect to the balancing body 1 are defined as follows using a Cartesian coordinate system x, y, z. Coordinates x, y span a horizontal plane x, y, with the base wall 3 lying in the horizontal plane x, y. For a rectangular balancing body 1, the coordinate x runs along the shorter edge and defines a width direction or lateral direction or transverse direction, and the coordinate y runs along the longer edge of the base wall 3 and defines a longitudinal direction, with the positive direction x defining a "front" and the negative direction x defining a "rear". End sides located in the longitudinal direction x are also referred to as front sides, and end sides located in the transverse direction y are referred to as cheeks. The side wall 4 thus has two front sides 4b, 4d and two cheeks 4a, 4c. The wall recesses 5 are each formed in a cheek 4a, 4c.The coordinate z is perpendicular to the floor wall 3 and defines a vertical or height direction, where the positive direction z defines “top” and the negative direction y defines “bottom”.

[0030] The receiving area 6 is thus defined on the upper side of the base wall 3. On the underside of the base plate 3, two longitudinally extending shoulders 7 are formed at the lateral edges, which can serve to receive guide rails or the like, for example, in a receiving area on the rotor of a centrifuge, or rollers of a roller conveyor in a transport system. The shoulders 7 have respective approach slopes 17 ( Fig. 2) appears.

[0031] In this embodiment, the base body 2 of the balancing body 1 is made of plastic, preferably a thermoplastic or a duroplastic.

[0032] A coupling 8 for manipulation by a gripper or the like is provided on the front end face 4b. The coupling has a retaining hole 9 for this purpose. The coupling 8 is preferably magnetic or made of a ferromagnetic material to facilitate coupling. In this exemplary embodiment, the coupling 8 is designed as a sheet metal element that is mounted to the front end face 4b by means of fastening screws 10. Alternatively, the coupling 8 can also be formed integrally with the front end face 4b and, for example, have a magnetic sleeve.

[0033] A base 11 is formed in the floor wall 3, which leads via a step 12 to a recess or depression 13. The height of the step 12 and the width of the depression 13 are dimensioned such that a skirt 55 (cf. Fig. 5B) of the reaction vessel unit 50 can be received in the depression 13. It can be provided that the reaction vessel unit 50 rests with the undersides 56 of the reaction vessels 51 or with the ribs 58 on the base 11 or alternatively with the skirt 55 on the depression 13.

[0034] A receiving area 14 for trim weights 16, 16' is provided on the balancing body 1. In this exemplary embodiment, the receiving area 14 has a plurality of recesses 15, here in the form of longitudinal slots, which are formed on the underside of the bottom wall 3. In modifications, the recesses 15 can also be formed on the upper side of the bottom wall 3 or be formed continuously in the bottom wall 3. The recesses are each designed to accommodate one trim weight 16, 16' or several trim weights 16, 16'.

[0035] The trim weights 16, 16' can be fixed in the recesses 15 by friction, form fit, or material bonding, such as gluing or welding. The trim weights 16, 16' can also be fixed, for example, by means of a casting compound 30 ( Fig. 3) be firmly connected to the base body 2. The trim weights 16, 16' can also be formed from a potting compound, for example in the form of a highly compacted, polymer-bonded metal powder, or can be potted during the manufacture of the base body 2 or formed by an additive process, and possibly even integrated by an additive process.

[0036] In this exemplary embodiment, the trim weights 16, 16' are non-magnetic or amagnetic. The base body 2 is also magnetically inactive. Thus, the entire balancing body 1 is non-magnetic or amagnetic, possibly except for the coupling 8 and / or fastening screws 10. This prevents the balancing body 1 from adhering to another balancing body 1 or to a carrier 73 designed as a magnetic carrier (see below). The trim weights 16, 16' are preferably made of a non-magnetic or amagnetic material that has a comparatively high density compared to the base frame 73, such as lead, copper, brass, another metal, an alloy or other compound, or of a ceramic.Particularly advantageously, the trim weights 16, 16' can be manufactured from a semi-finished product in bar form, so that the desired trim weight 16, 16' can be produced by simply cutting to length and optionally deburring or other finishing. Fine-tuning of the mass and mass distribution of the trim weights 16, 16' can be achieved, for example, by filing, scraping, drilling, or other machining processes. The semi-finished product can have a fixed width adapted to the dimensions of the recesses 15. The thickness of the semi-finished product can vary or be available in several staggered sizes, limited by the depth of the recesses 15.

[0037] By changing the arrangement of the trim weights 16, 16' in the recesses 15, different weight distributions can be achieved and thus different balancing bodies 1, 1' can be produced. In the present exemplary embodiment, the base body 2 has three recesses 15 that extend symmetrically along the longitudinal direction y. The balancing body 1 has, for example, in two lateral recesses 15, a short trim weight 15 of a first length s and in a central recess 15, a long trim weight 16' of a second length s' ( Fig. 1B, Fig. 4A). A width w and a thickness t are the same for both trim weights 16, 16'. In another balancing body 1', the two lateral recesses 15 can each accommodate a long trim weight 16', while the central recess 15 remains empty ( Fig. 4B). It is understood that the two sizes of trim weights 16, 16' shown are merely examples. Trim weights 16, 16' can be provided and used in many sizes and masses. The trim weights 16, 16' can be Fig. 3, be permanently cast with a casting compound 30 or be arranged interchangeably in the recesses 15. The dimensions of the trim weights 16, 16' are limited only by the slot length s0, slot width w0 and slot depth t0 of the recesses 15 (cf. Fig. 3, Fig. 4A).

[0038] The trim weights 16, 16' make it possible to provide balancing bodies 1 with a defined mass, center of gravity, mass moment of inertia and local weighted area moment of inertia relative to a cross-section to the longitudinal axis y.

[0039] The mass moment of inertia can be expressed as a weighted area moment of inertia by an expression of the form Θ=∫e(y,r,φ)r2dV where Θ is the moment of inertia, a local density, r is a distance from the rotor axis R, φ is an angular coordinate, and V is a volume. The local density is obviously dependent on the locally present material in a local volume unit dV. In the case of the balancing body 1, this can be a material of the base body 2, a material of the trim weight 16, 16', a material of the potting compound 30 or air in the case of free spaces, possibly also a material of the coupling 8 or of holding / connecting elements such as fastening screws 10 or the like.

[0040] The local weighted moment of inertia can accordingly be expressed by an expression of the form Θ′(y)=∫e(y,r,φ)r2dF where F is a cross-sectional area.

[0041] This allows a counterweight or balancing weight to be created for any arrangement of supports 73 for or with reaction vessel unit 50.

[0042] Reaction vessel units 50 may have the shape of a microtiter plate ( Fig. 5), but the application of the invention is not limited thereto. The individual reaction vessels 51 of a microtiter plate are also referred to as wells, which are usually arranged in a predetermined, regular grid of rows 52 and columns 53. The grid thus specifies the number of reaction vessels 51.

[0043] Microtiter plates are available in various sizes and designs. The base area usually corresponds to the ANSI standards recommended by the Society for Biomolecular Screening (SBS) of I = 27.76 mm × w = 85.48 mm × h = 14.35 mm. The length (I) and width (b) are fixed, but the height (h) can vary. Common grid dimensions for microtiter plates are listed in the table below: Näpfchen Anzahl Raster Füllvolumen (µl) 6 2×3 2000...5000 12 3×4 2000...4000 24 4×6 500...3000 48 6×8 500...1500 96 8×12 100...300 384 31×24 30...100 1536 32×48 5...15 3456 48×72 1...5

[0044] The name of a microtiter plate depends on the number of wells. For example, a microtiter plate with 24 wells is called a 24-well plate, a microtiter plate with 384 wells is called a 384-well plate, and so on. The wells can have different bottom shapes, such as F-bottom (flat bottom), C-bottom (flat bottom with slightly rounded edges), V-bottom (conical bottom), or U-bottom (U-shaped recess, see [Fig. Fig. 5B). The cells can have different cross-sectional shapes, such as round, oval, elliptical, square, diamond-shaped, or hexagonal, with polygonal shapes also having rounded edges.

[0045] Assays, among other things, are performed in such reaction vessel units 50. These are, for example, standardized reaction sequences for detecting a substance or reaction using a specific method, particularly in the field of molecular biology. Washing steps must also be performed, particularly at the end of a campaign, but possibly also at certain times during the assay, to completely or partially empty the contents of the reaction vessels 51.

[0046] For washing reaction vessel units 50, a centrifuge 60 can be used, as shown for example in Fig. 6 is shown.

[0047] The centrifuge 60 has a housing 61 having a bottom wall 61a, a rear wall 61b, a front wall 61c, and a cover 61d. A drainage channel 61e is formed in the bottom wall 61a and is connected to a drain. The housing 61 encloses a rotor chamber 62. Between the rear wall 61b and the front wall 61c, each rotatably mounted about a rotor axis R, extends a rotor shaft 63, which is coupled to a rotor drive 64 for rotation about the rotor axis R. A rotor 70 is attached to the rotor shaft 63. The rotor 70 has a base frame 71 with two receiving locations 72 for receiving reaction vessel units 50 arranged on a carrier 73 (see also Fig. 7A, Fig. 7B). The front wall 61c has a window 61f through which the rotor chamber 62 can be loaded from the outside. Outside the rotor chamber 62, a balcony 65 is attached to the front wall 61c. A support 73 for reaction vessel units 50 can be arranged on the balcony 65. The balcony 65 is aligned with the window 61f at least to the extent that a support 73 arranged thereon, with the reaction vessel unit 50 arranged thereon, can be moved from the balcony 65 into the rotor chamber 62 and back again from the rotor chamber 62 to the balcony 65. The window 61f can be closed by a flap 66. For moving the support 73, a displacement rod 67 is provided, which can be moved through the rotor chamber 62 by means of a linear drive 68. The sliding rod 67 has a coupling element 67a for coupling with the coupling 76 of the carrier 73.For loading, the rotor 70 is rotated with the sliding rod 67 retracted into a position in which one of the receiving locations 72 is aligned with the window 61f and the balcony 65, then the sliding rod 67 is extended and moved through the rotor chamber 62, the receiving location 72 of the rotor 70 and the window 61f until the coupling element 67a couples with the coupling 76 on the carrier 73, the carrier 73 with the reaction vessel unit 50 arranged thereon is pulled onto the receiving location 72, the coupling element 67a is decoupled from the coupling 76 and the sliding rod 67 is fully retracted so that the sliding rod 67 does not interfere with the rotation of the rotor 70.For removal, the rotor 70 is rotated again with the displacement rod 67 retracted into a position in which the loaded receiving space 72 is aligned with the window 61f, then the displacement rod 67 is first extended until the coupling element 67a couples with the coupling 76 on the carrier 73, then moved further through the rotor space 62, the receiving space 72 of the rotor 70 and the window 61f until the carrier 73 with the reaction vessel unit 50 arranged thereon is arranged on the balcony 65, the coupling element 67a is decoupled from the coupling 76 and the displacement rod 67 is fully retracted so that the displacement rod 67 does not interfere with the rotation of the rotor 70, or only partially retracted in order to be kept ready for a further loading process.

[0048] A dispensing module 69 with one or more dispensing heads 69a, each with one or more dispensing nozzles 69b, can also be mounted on the front wall 61c above the balcony 65. The dispensing module can be used to fill the reaction vessels 51 of the reaction vessel unit 50 with a dispensing liquid or various dispensing liquids. Dispensing can be carried out column by column with respect to the columns 53 of reaction vessels 51 of the reaction vessel unit 50. For this purpose, the displacement rod 67 can also be used, which can be precisely and reliably positioned by means of the positioning drive 68 and due to the rigidity of the displacement rod 67 itself and the coupling element 67a, as well as a low-vibration or vibration-free design of the positioning drive 68, so that exact and tightly timed filling can be achieved by the dispensing unit 69.

[0049] The centrifuge is the subject of several patent applications, with reference being made in particular to WO 2017 / 125598 A1 with regard to the design with a sliding rod and positioning drive, to WO 2018 / 234420 A1 with regard to the design with a drainage channel, to EP 4151315 A1 with regard to a discharge device, and to EP 4151315 A1 and WO 2023 / 020981 A1 with regard to the dispensing unit, as far as the illustrated embodiment is concerned.

[0050] The receiving locations 72 are formed diametrically opposite with respect to the rotor axis R on the base frame 71 of the rotor 70 ( Fig. 7A, Fig. 7B). In the figure, a carrier 73 is accommodated at a first (upper in the figure) receiving location 72, while the above-described balancing body 1 is accommodated at a second (lower in the figure) receiving location 72. The balancing body 1 is designed to compensate for an imbalance that occurs when the rotor 60 rotates with the carrier 73 and reaction vessel unit arranged thereon. To simplify the illustration, a reaction vessel unit is shown in the Fig. 7A, Fig. 7B omitted.

[0051] The receiving locations 72 each have a receiving contour 74, which negatively replicates an outer contour of the received carrier 73 with reaction vessel unit, at least to the extent that this is expedient for the secure reception and trouble-free transfer of the carrier 73 into and out of the rotor 70. For example, the receiving contour 74 has two lateral guide surfaces 74a for engagement with a side wall 75a of the carrier 73. The lateral guide surfaces 74a are each delimited at the bottom by a lower guide surface 74b, which extends inward and serves as a rail-like support for shoulders on the bottom wall 3 of the carrier 73. The lateral guide surfaces 74a are each delimited at the top by a first upper stop surface 74c, which extends inward and serves as a support for the upper edge of an apron 55 of a reaction vessel unit 50 arranged on the carrier 73.In the context of the rotor, "top" corresponds to a direction away from the rotation axis R, bottom to a direction towards the rotation axis R. The first upper stop surfaces are each delimited inwards by a lateral limiting surface 74d, which extends upwards and serves for the lateral support of a reaction vessel unit 50 arranged on the carrier 73. The lateral limiting surfaces 74d are each delimited at the top by a second upper stop surface 74e, which extends inwards and serves for the upper guidance and securing of a reaction vessel unit 50 arranged on the carrier 73. The lower guide surfaces 74b each end inwards in a recess 74f, which extends downwards and exposes further structures of the bottom wall 75b of the carrier 73.

[0052] In the present embodiment, the carrier 73 is a magnetic carrier. Such a magnetic carrier is used to exert a magnetic force on magnetic particles (“beads”) that are suspended in solutions in the reaction vessels in order to adsorb biomolecules from these solutions onto their surface for further analysis. The carrier 73 has a base body 75 with a side wall 75a and a bottom wall 75b, which define a receiving area 75c for a reaction vessel unit 50. The base body 75 has an outer contour that is adapted for receiving in one of the receiving locations 72 of the rotor 70. The carrier 73 has a magnet arrangement 77 with a plurality of magnets 77a arranged in a matrix. The matrix of the magnet arrangement 77 corresponds to the grid of the reaction vessels 51 of a reaction vessel unit 50 ( Fig. 5A, Fig. 5B). In this respect, the magnet carrier 1 is adapted to a specific shape of reaction vessel unit 50. An auxiliary magnet arrangement 78 with a plurality of auxiliary magnets 78a is arranged around the magnet arrangement 77. The auxiliary magnets 78a are arranged outside an edge of the matrix of the magnet arrangement 77 in the extension of a row or column of the matrix. The auxiliary magnets 78a arranged at the edges serve to equalize, amplify, or stabilize the edge-side magnetic field of the magnet arrangement 77. They thus form magnetic force increasing means designed to increase the magnetic effect of the magnets 77a of the magnet arrangement 77 located at the edges of the matrix. For better alignment of the magnetic field toward the receiving area 75c of the carrier 73, a magnetic yoke 79 in the form of a back plate is also provided on the side of the bottom wall 75b of the carrier 73 facing away from the receiving area 75c.During centrifugation, the magnetic particles and reactants bound to them can be selectively retained in the reaction vessels 51 by the magnetic effect of the magnet arrangement 77, supported by the magnetic effect of the auxiliary magnet arrangement 78, while residual liquid is washed out of the reaction vessels. Because the auxiliary magnets 78a of the auxiliary magnet arrangement 78 are located particularly along the longitudinal edges of the magnet arrangement 77, i.e., in the region of greatest centrifugal force during centrifugation, a more uniform magnetic retention effect across the transverse axis of the reaction vessel unit can also be achieved by the auxiliary magnet arrangement 78. Such a magnetic carrier is the subject of another utility model, which was filed on the same day as the present utility model and to whose disclosure content reference is made in full in this regard.The type and design of the carrier 73 is chosen here entirely by way of example and solely for illustrative purposes. The carrier 73 can also be designed entirely differently. In particular, it is understood that the receiving contour 74 can also accommodate carriers that are not magnetic carriers, provided the outer contour of the carrier is adapted for reception in one of the receiving locations 72 of the rotor 70. Nevertheless, the balancing body 1 unfolds its advantages particularly in conjunction with a magnetic carrier that has a high mass compared to conventional carriers and, depending on the type of reaction unit and the desired properties of the magnetic field, a specific mass distribution. The balancing body 1 is therefore adapted, through its trim weights 16, 16', especially for balancing purposes to comparatively heavy carriers 73, such as in particular the magnetic carrier of the type shown here.By means of the trim weights 16, 16', the balancing body 1 can be adapted to the respective carrier 73 in terms of mass and / or center of gravity and / or mass moment of inertia and / or local weighted area moment of inertia with respect to the rotor axis R.

[0053] The balancing body 1 according to the invention has an outer contour similar to the carrier 73 insofar as it is suitable for receiving it in one of the receiving locations 72 of the rotor 70. Compare also the representation of a cross section of a carrier 73 designed as a magnet carrier in Fig. 8 with that of the balancing body 1 according to the invention in Fig. 3.

[0054] For further balancing, an empty reaction vessel unit 50 or a reaction vessel unit 50 whose reaction vessels 51 are captively filled with a balancing mass whose mass corresponds to an assumed initial mass of the filling of the reaction vessels 51 of the reaction vessel unit 50 to be washed can also be accommodated on the balancing body 1.

[0055] With the help of the trim weights 16, 16', the weight distribution of the balancing body 1 can be adjusted to the weight distribution of a carrier 73 for reaction vessel units 50. In particular, a balancing body 1 with a specific arrangement of trim weights 16, 16' can be adapted to a specific type of carrier 73. This is particularly advantageous if the carrier 73 is a magnetic carrier, because the magnets 77a and, if applicable, auxiliary magnets 78a of a magnetic carrier have a comparatively high mass, which can generate a considerable imbalance of the rotor 70 during centrifugation. The high mass of a magnetic carrier can be compensated for by the trim weights 16, 16', so that the imbalance can be reduced or eliminated.It is particularly advantageous if the center of gravity position and / or the mass moment of inertia and / or the local weighted area moment of inertia in each cross section of the magnet carrier is also adjusted to the carrier 73 by the dimensioning and arrangement of the trim weights 16, 16'.

[0056] In other words, preferably at least one of the following relations applies mbalance body = mcarrier rg,balance body=rg,carrier yg,balance body=yg,carrier ΘBalance body=ΘCarrier ∀y:Θ′balancing body(y)≡Θ′carrier(y)

[0057] The local density of the carrier 73 also depends on the locally present material. This can be a material of the base body 75, possibly a material of the magnets 77a or auxiliary magnets 78a, a material of the back plate 79 or air in the case of free spaces, possibly also a material of the coupling 76 or of holding / connecting elements such as fastening screws 79a or the like.

[0058] By designing the balancing body 1 and the support 73 largely symmetrically with respect to a center plane in the transverse direction xz, i.e., by designing the base bodies 2, 75 largely symmetrically, by arranging the trimming bodies 16, 16', the magnet arrangement 77, the auxiliary magnet arrangement 78, and the back plate 79 largely symmetrically, as well as by designing and arranging the couplings 8, 76 in an asymmetrical but identical manner, deviation moments can be largely avoided. The equivalence in the last of the relationships given above is to be understood as meaning that the local weighted moment of inertia Θ'(y) of the balancing body 1 and the support 73 is ideally the same in every cross-section, but at least balances or averages out over the length. For example, it is not necessary to exactly replicate the arrangement of the magnets 77a and auxiliary magnets 79a of a support 73 designed as a magnet support.Rather, this arrangement can be averaged out by rod-like trim weights 16, 16'.

[0059] According to the invention, a system of a carrier 73 and a balancing body 1, 1' can also be created, each having an identical reference contour for mounting in the mounting locations 72 of the rotor 70, and wherein the balancing body 1, 1' is adapted to the carrier 73 with regard to mass and / or center of gravity and / or mass moment of inertia and / or local weighted area moment of inertia. A series of systems of carriers 73, in particular magnetic carriers, each having different grids of retaining magnets 77a corresponding to a grid of the reaction vessels 51 of a respective reaction vessel unit 50 and / or different arrangements of auxiliary magnets 79a, and balancing bodies 1, 1', each adapted to a respective carrier 73 in terms of mass and / or center of gravity and / or mass moment of inertia and / or local weighted area moment of inertia, can also be created.The mass moment of inertia and the local weighted area moment of inertia are each related to the position on the rotor 70, i.e., in particular, a predetermined distance from the rotor axis R. For example, the height of the support 73 and the balancing body 1 can be determined by the height of the reaction vessel unit 50, because the package of support 73 and reaction vessel unit 50 should not exceed a certain clearance in the rotor 70 (approximately 2 mm). This results in the provision of supports 73 and balancing bodies 1 of different heights. In currently known practical embodiments of the rotor 73, the height of the receiving locations 72 is, for example, 19 mm or 28 mm.

[0060] The mass distribution on the balancing body 1 can be designed such that a mass in an outer third with respect to a width direction is lower than in a middle third of the balancing body with respect to the width direction, for example by at least 10% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90%. Conversely, it can also be provided that a mass in the middle third is lower than in an outer third of the balancing body, for example by at least 10% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90%. Depending on the type of corresponding carrier, it can also be advantageous if the balancing body has a center of gravity that lies below half the height of the balancing body.

[0061] It is clear that all criteria for the design of the balancing body with regard to mass distribution and moments of inertia are always applicable and constitute independent aspects of the invention, regardless of whether the balancing body is magnetic or not. In particular, if the corresponding support for which the balancing body is designed is not a magnetic support, it is not essential that the balancing body be non-magnetic or amagnetic.

[0062] It should be noted that the balancing body 1 only optionally has the receiving area 6 with base 11 and recess 13. Optionally, such a receiving area 6 for the reaction vessel unit can also be omitted. For example, the base body 2 of the balancing body 1 can be designed to integrally replicate the mass distribution of a reaction vessel unit 50, or a structure that replicates the mass distribution of a reaction vessel unit 50 can be attached to the base body 2.

[0063] A method for manufacturing a balancing body may include: • Forming the balancing body in such a way that it is designed for weight compensation on a rotor of a centrifuge, wherein the balancing body is designed separately from the rotor and for receiving in a receiving location for carriers for reaction vessel units on the rotor, wherein the balancing body is non-magnetic or amagnetic.

[0064] The formation of the balancing body can include: • Forming a base body which is designed to be received at the receiving location on the rotor, • Forming at least one trim body, and • Inserting the trim body into or onto the base body.

[0065] Both the material of the base body and the material of the trim body are non-magnetic or amagnetic. In particular, the material of the trim body can be different from the material of the base body. Preferably, the material of the base body is a plastic, in particular a thermoplastic or thermoset. The base body is preferably produced by injection molding, deep drawing, or additive or machining processes, for example milling, optionally supplemented by further machining or grinding steps for final or fine machining. Further preferably, the material of the trim body is a non-magnetic or amagnetic metal, such as non-magnetic steel, lead, copper, brass, or an alloy thereof, and / or a ceramic. Particularly preferably, the material of the trim body has a density of at least 6 g / cm 3 on.

[0066] Forming the trim body may include: • Providing a semi-finished product, particularly in bar form, • Cutting the semi-finished product to length, • optional deburring of the cut semi-finished product, • optional fine machining of the cut semi-finished product to produce a desired mass or mass distribution, • Arranging the trim body on the base body, • Optionally fixing or fastening the trim body to the base body.

[0067] For this purpose, the formation of the base body can comprise the formation of at least one receiving area for trimming bodies, for example one or more slot- or groove-shaped recesses, in particular depressions and / or openings, preferably on or in a bottom wall, as described in further detail above.

[0068] By receiving and fixing or fastening, the trim body can be arranged fixedly or interchangeably on the base body. Arranging the trim body can involve inserting, pushing in, or the like. Fixing or fastening can involve screwing, clipping, captive insertion, locking, frictional or positive locking, or any other suitable connection method, or encapsulation with a potting compound. Alternatively, the trim body can be encapsulated during the manufacture of the base body. The base body and / or the trim body can also be manufactured sequentially or integrated in a single step using additive processes.

[0069] Particularly preferably, the balancing body is designed with respect to a corresponding support for reaction vessel units in such a way that when both the balancing body and the corresponding support are accommodated on respective, in particular diametrically opposite, receiving locations of a rotor of a centrifuge, an imbalance generated by the support, optionally with the reaction vessel unit arranged thereon, is reduced or eliminated.

[0070] For design details and further details, reference is also made to the above description of the balancing body 1.

[0071] Thus, the production of the balancing body can also include: • Mounting of the balancing body and a carrier for reaction vessel units, if necessary with the reaction vessel unit arranged thereon, on respective, in particular diametrically opposite, mounting locations of a rotor of a centrifuge, • Rotating the rotor, • Determining an imbalance, • if necessary: ​​adjusting the balancing body, in particular by reworking a trimming body or a casting compound or a base body of the balancing body, removing a trimming body or adding another trimming body.

[0072] The above steps can be repeated iteratively.

[0073] Optionally, the mass and moment of inertia of the balancing body 1 with respect to the rotation axis R can be determined in a CAD program and the weight can be adjusted even more precisely to the support 73 during construction.

[0074] With the balancing body described above, a method for operating a centrifuge, in particular for washing reaction vessel units, can be carried out with the following steps: • Arranging the balancing body described above, optionally with a reaction vessel unit arranged thereon, at a first receiving location of a rotor of a centrifuge, • Arranging a support for reaction vessel units with a reaction vessel unit arranged thereon in a second receiving location of the rotor of the centrifuge, preferably diametrically opposite the first receiving location, in particular with openings of reaction vessels of the reaction vessel unit directed radially outwards with respect to a rotor axis of the rotor, and • Rotating the rotor at a predetermined angular speed, which is particularly adapted to remove a substance located in the reaction vessels from the reaction vessels.

[0075] The removal can also be selective. For example, a liquid can be removed from the reaction vessels, while particles retained by mechanical or other effects remain in the reaction vessels. This can particularly relate to magnetic particles that are attracted by magnets integrated into the carrier. It can also relate to substances that are held in a wall, in particular the bottom wall, of the reaction vessels by capillary action, or substances that are held by a hydrophilic or lipophilic coating or design on a wall, in particular the bottom wall, of the reaction vessels. Other purposes, such as settling or compacting a substance in the reaction vessels of a reaction vessel unit arranged with openings pointing radially to the rotor axis, can also be achieved by the method.

[0076] During rotation, vibrations of the rotor can be measured. If an incipient imbalance is detected, this can be interpreted as an indication that the active reaction vessel unit has been successfully emptied.

[0077] For further details, please refer to the above description of the balancing body 1.

[0078] The present invention has been explained above with reference to preferred embodiments. However, it is understood that the invention is not limited by individual features of the embodiments, but is defined solely by the independent patent claims in their broadest sense. Unless included in the respective independent patent claim, all individual features disclosed in connection with an embodiment or a subclaim are to be considered optional, even if the individual feature in question is present in all embodiments.Each individual feature that solves a technical problem compared to the prior art is suitable, in isolation or in any combination with other features described and / or shown herein, to define a separate subject matter of the invention, even if it was only described and / or shown in conjunction with other features of an embodiment. It is further understood that each feature described and / or shown in connection with one embodiment can also be applied to any other embodiment, insofar as this is technically possible, and should be considered disclosed to that extent.

[0079] For example, it has been described that the balancing body 1 is designed to accommodate a reaction vessel unit. However, this is not mandatory. Rather, the balancing body can also be adapted and dimensioned in terms of mass, mass distribution, center of gravity, mass moment of inertia, and / or weighted area moments of inertia to a support 73 with the reaction vessel unit 50 arranged thereon.

[0080] Likewise, the described recesses 7, and even more so the approach slopes 20, are completely optional.

[0081] Similarly, all features described in connection with an embodiment are to be considered optional as long as they are not absolutely necessary for the claimed invention and the problem solved thereby.

[0082] The described and illustrated embodiment assumes that the balancing body 1 is arranged on the rotor 70 with the longitudinal direction y parallel to the rotational axis R of the centrifuge 60, and accordingly, the recesses 15 with the trim weights 16, 16' are arranged primarily along the longitudinal axis y. If the balancing body 1 is arranged on the rotor 70 with the longitudinal direction y transverse to the rotational axis R of the centrifuge 60, the recesses 15 with the trim weights 16, 16' can accordingly be arranged primarily transverse to the longitudinal axis y.

[0083] It is further understood that the centrifuge 60 shown here is purely exemplary and does not limit the invention with respect to the balancing body 1 in any way, unless expressly described or claimed. Thus, in particular, the rotor 70 shown and described here serves solely to illustrate the application of the invention. The rotor 70 can be designed quite differently in practice. For example, the lower guide surface 74b of the rotor 70 can also be a simple shoulder, from which the shoulder 7 recesses, so that the support 73 rests with the bottom wall 75b or the magnetic yoke 79 on the recess 74f. For example, the recess 74c can also be omitted entirely. It is obvious that numerous further modifications are conceivable which do not affect or limit the present invention. List of reference symbols and formula symbols 1 balancing body 2 basic bodies 3 floor wall 4 side wall 4a, 4c cheeks 4b, 4d front sides 5 Wall recess 6 Receptacle area for reaction vessel unit 7 paragraph 8 Clutch 9 retaining hole 10 fixing screws 11 bases 12th level 13 Lowering 14 Trim weight storage area 15 Recess / slot 16, 16' trim weight 17 approach slope 30 Casting compound 50 reaction vessel units 51 Reaction vessel 52 lines 53 column 54 basic bodies 55 apron (skirt) 56 Bottom 57 wall 58 Stiffening rib 60 centrifuge 61 housings 61a floor wall 61b Rear wall 61c front wall 61d cover 61e Drainage channel 61f window 62 Rotor chamber 63 Rotor shaft 64 Rotor drive 65 Balcony 66 flap 67 sliding rod 68 Positioning drive 69 Dispensing module 69a Dispensing head 69b Dispensing nozzle 70 rotor 71 base frame 72 recording places 73 carriers 74 Recording contour 74a Lateral guide surface 74b Lower guide surface 74c First upper stop surface 74d Lateral boundary surface 74e Second upper stop surface 75 basic bodies 75a side wall 75b floor wall 75c Receptacle area for reaction vessel unit 76 Clutch 77 Magnet arrangement 77a Magnet / retaining magnet 78 Auxiliary magnet arrangement 78a Auxiliary magnet 79 Back plate / magnetic yoke 79a Fixing screw A loading position B Unloading position F Area R rotor axis V Volume b Width (reaction vessel unit) h Height (reaction vessel unit) I Length (reaction vessel unit) r radius s, s' length (trim weight) s0 slot length t strength (trim weight) t0 slot depth w Width (trim weight) w0 slot width x transverse direction y longitudinal direction z Vertical direction Θ moment of inertia Θ' local weighted area moment of inertia φ angular coordinate density

[0084] The above list is an integral part of the description. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2021 / 138485 A1

[0002] US 11,117,142 B2

[0002] WO 2015 / 018878 A2

[0003] WO 2017 / 125598 A1

[0049] WO 2018 / 234420 A1

[0049] EP 4151315 A1

[0049] WO 2023 / 020981 A1

[0049]

Claims

[1] Balancing body (1) for weight compensation on a rotor (70) of a centrifuge (60), wherein the balancing body (1) is designed separately from the rotor (70) and for receiving in a receiving location (72) for supports (73) for reaction vessel units (50) on the rotor (70), wherein the balancing body (1) is non-magnetic or amagnetic. [2] Balancing body (1) according to claim 1, wherein the balancing body (1) has at least one trimming weight (16, 16'), wherein the trimming weight (16, 16') is made of a non-magnetizable material, which preferably has a density of at least 6 g / cm 3 in particular metal, preferably non-magnetic steel, lead, copper, brass or an alloy thereof, and / or ceramic. [3] Balancing body (1) according to claim 2, wherein the balancing body (1) comprises a base body (2) made of plastic, which has the trim weight (16, 16') integrally or by which the trim weight (16, 16') is received, wherein the base body (2) is produced in particular by an additive process and / or a casting process and / or a machining process, for example milling. [4] Balancing body (1) according to claim 3, wherein the trim weight (16, 16') is arranged on the base body (2), preferably arranged in an exchangeable manner. [5] Balancing body (1) according to one of claims 2 to 4, wherein the trim weight (16, 16') is cuboid-shaped and is preferably made of a rod-shaped semi-finished product. [6] Balancing body (1) according to one of claims 2 to 5, wherein the base body (2) has a receiving area (14) for trim weights (16, 16'). [7] Balancing body (1) according to claim 6, wherein the receiving area (14) has one or more slot- or groove-shaped recesses (15), in particular depressions and / or openings, which preferably extend parallel to one another. [8] Balancing body (1) according to claim 6 or 7, wherein the receiving area (14) has a plurality of recesses (15) which are arranged symmetrically around a plane of symmetry of the base body (2). [9] Balancing body (1) according to one of claims 6 to 8, wherein trim weights of different lengths (s, s') or different thicknesses (t) or different widths (w) or different masses are accommodated in the receiving area (14). [10] Balancing body (1) according to one of claims 1 to 9, wherein the balancing body (1) has a mass of at least 50 g or at least 100 g or at least 150 g or at least 200 g and / or of at most 650 g or at most 550 g or at most 450 g or at most 350 g. [11] System consisting of a carrier (73), in particular a magnetic carrier, for reaction vessel units (50) and a balancing body (1) according to one of claims 1 to 10, wherein the balancing body (1) and the carrier (73) have an identical reference contour, wherein the balancing body (1) is adapted to the carrier (73) with regard to the center of gravity position and / or mass moment of inertia and / or local weighted area moments of inertia with respect to a rotation axis (R) of the rotor (70). [12] System according to claim 11, wherein the balancing body (1) has the same mass as the carrier (73). [13] System according to claim 11 or 12, wherein the balancing body (1) has the same mass moment of inertia and / or the same local weighted area moments of inertia in each cross section with respect to the / a rotational axis (R) of the rotor (70) as the carrier (73), wherein the balancing body (1) in particular has a mass distribution such that, with a weight corresponding to a corresponding carrier (73), in particular a magnetic carrier, which can be received in the receiving location (72) of the rotor (70), a mass moment of inertia and / or local weighted area moments of inertia with respect to a rotational axis (R) of the rotor (70) is / are created which corresponds / correspond to that of the corresponding carrier (73) with respect to the rotational axis (R) of the rotor (70). [14] System according to one of claims 11 to 13, wherein the balancing body (1) has the same center of gravity position with respect to the reference contour as the carrier (73). [15] System according to one of claims 11 to 14, wherein the reference contour is a contour that is complementary to a receiving contour for receiving the carrier (73) on the rotor (70), wherein the reference contour is in particular an outline or a surface of a bottom wall (3) of the carrier (73) and of the balancing body (1). [16] System according to one of claims 11 to 15, wherein the carrier (73) is a magnetic carrier, wherein the magnetic carrier has a receiving area (14) for receiving a reaction vessel unit (50) and a magnet arrangement (77) with magnets (77a) arranged in a matrix, wherein preferably in addition to the magnet arrangement (77) an auxiliary magnet arrangement (79) of auxiliary magnets (79a) arranged outside the magnet arrangement (77) in order to increase a magnetic effect of the magnets (77a) of the magnet arrangement (77) located on at least one edge, preferably a plurality of edges, particularly preferably opposite edges, of the matrix.

Images