Cartridge for a rotation-based analysis method which utilizes a heat input

Abstract

The invention relates to a cartridge (1) for a rotation-based analysis method. The cartridge (1) has a main part (2), which extends in a planar manner and in which a channel and chamber structure (4) is formed, and a cover body (18), which is secured to the main part (2) and is arranged on a main part (2) upper face (20) facing away from a heat input side (12) and which covers a chamber (6, 40) of the main part (2). The main part (2) and / or the cover body (18) has a number of holding openings (24), and the cover body (18) or the main part (2) has a number of latching hooks (22), each of which is paired with one of the optionally multiple holding openings (24), wherein a foot limb (50) of the latching hook (22) protrudes from the cover body (18) or the main part (2) in the direction of the main part (2) or the cover body (18), and the foot limb (50) transitions into a central part (52) which is bent in a U-shaped manner and which transitions into a free limb (54) that is oriented back in the direction of the cover body (18) or the main part (2) and terminates with a free end (56). The latching hook (22) or each latching hook has a projection (58) with a latching surface (60) on the free end-side, said latching surface being oriented in the direction of the free end (56). The central part (52), which is bent in a U-shaped manner, of the latching hook (22) or of each latching hook engages through the paired holding opening (24), thereby forming a latching connection.

Description

[0001] The invention relates to a cartridge for a rotation-based analysis method using heat input.

[0002] Rotation-based analysis methods are used in the medical field using so-called cartridges, which often have a microfluidic channel and chamber structure. They are typically used to analyze genetic material, usually in the form of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid), in addition to scientific genetic analyses and the like, to test for existing diseases or to detect pathogens in general. For this purpose, specific regions of the genetic material (DNA or RNA) contained in a sample—e.g., a swab, a blood sample, or the like—must be amplified. In the case of the detection or analysis of RNA in a sample (e.g., to detect a virus), this is first transcribed into DNA using a process known as "reverse transcription" and then amplified.

[0003] To replicate DNA, the polymerase chain reaction (PCR) is typically used in a liquid reaction mixture. DNA typically exists in the form of a double helix structure consisting of two complementary single DNA strands. During PCR, the DNA is first separated into two single strands by raising the temperature of the liquid reaction mixture to typically 90-96 degrees Celsius ("denaturation phase").

[0004] The temperature is then lowered again ("annealing phase", typically to a range of 50-70 °C) to enable the specific attachment of so-called primer molecules to the single strands. The primer molecules are complementary, short DNA strands that bind to the single strands at a defined location. The primer molecules (also abbreviated to "primers") serve as a starting point for an enzyme, the so-called polymerase, which, in the so-called elongation phase, fills in the basic building blocks ("dNTPs") complementary to the existing DNA sequence of the single strand. Starting from the primer molecule, double-stranded DNA is again created. Elongation is typically carried out at the same temperature as in the annealing phase or at a slightly higher temperature, typically between 65 and 75 °C. After elongation, the temperature is raised again for the denaturation phase.

[0005] This cycling of the temperature in the liquid reaction mixture between the two to three temperature ranges is called "PCR thermocycling" and is typically repeated in 30 to 50 cycles. In each cycle, the specific DNA region is amplified. Typically, thermocycling of the liquid reaction mixture is achieved in a reaction vessel by controlling the external temperature. The reaction vessel is located, for example, in a thermal block, in which PCR thermocycling is implemented by heating and cooling a solid in thermal contact with the reaction vessel, thereby transferring heat to and from the liquid. Alternative heating and cooling concepts for implementing PCR thermocycling include temperature control of fluids (especially air and water) flowing around the reaction vessel, as well as radiation-based concepts, e.g., by introducing heat through IR radiation or laser radiation.In the case of rotation-based processes, a chamber in the aforementioned cartridge, for example, is used as a reaction vessel and heated accordingly. Additionally, the cartridge, which is usually shaped like a disc, is rotated.

[0006] As an alternative to the PCR thermocycling described above, methods such as isothermal amplification and isothermal immunoassays are also used as methods for analyzing (amplifying) DNA (or RNA) or for testing for diseases.

[0007] The cartridge may also have "attachments" that serve to stabilize it, improve handling, or support temperature control. However, due to the sometimes high rotation speed and / or temperature exposure, these attachments may become (at least partially) loose.

[0008] WO 2020 / 229578 A1, US 2013 / 149775 A1, and US 2016 / 305938 A1 are known from the prior art. WO 2020 / 229578 A1 discloses a system for unmasking protein antigens and nucleic acid targets from fixed biological samples. US 2013 / 149775 A1 discloses a system for detecting contaminants in biological samples. US 2016 / 305938 A1 discloses fluidic connections, methods, and devices for performing analyses in microfluidic systems.

[0009] The invention is based on the object of providing an improved cartridge.

[0010] This object is achieved according to the invention by a cartridge which is designed and provided for a rotation-based analysis method and which has the features of claim 1. Advantageous and partly inventive embodiments and further developments of the invention are set out in the subclaims and the following description.

[0011] The cartridge according to the invention is designed and intended for use in a rotation-based analysis method utilizing a preferably one-sided heat input. For this purpose, the cartridge has a flat, i.e. in particular essentially two-dimensional, base body in which a, in particular microfluidic, channel and chamber structure is formed, within the framework of which preferably several (process) chambers are connected to one another by means of channels. Furthermore, the cartridge has a cover body fastened to the base body, which is arranged on one side on an upper side of the base body facing away from a heat input side and covers at least one ("process") chamber of the channel and chamber structure of the base body. The base body and / or the cover body have a number of holding openings. The cover body or the base body (e.g.(i.e., vice versa) have a number of locking hooks, each associated with one of the possibly several holding openings. The (or in the case of.

[0012] several locking hooks (the respective) locking hook protrudes with a (preferably straight and elongated) "foot limb" from the cover body or the base body in the direction of the corresponding other component (i.e., the base body or the cover body). The foot limb thus "rests" on the cover body or the base body. The foot limb merges into a U-shaped bent middle section, which in turn merges into a (preferably straight and elongated) free limb. This free limb is directed back towards the cover body or the base body and terminates in a free end. The (or the respective) locking hook also has a shoulder on the free end with a locking surface which (i.e., a normal pointing from the locking surface into the surroundings) is directed towards the free end.The (or the respective) locking hook (in the intended assembly state of the cartridge) with its U-shaped bent middle part passes through the associated holding opening, forming the locking connection.

[0013] Compared to a conventional locking hook, the locking hook according to the invention (at least its free end) is advantageously not (or at least not substantially) subjected to tensile stress when the cover body is loaded in the disassembly direction, but rather to compressive stress and possibly also to bending and / or shearing. This leads to a different (elastic and possibly plastic) deformation behavior, which advantageously makes "unclipping," i.e., a (particularly undesirable) detachment of the locking surface from its counterpart, more difficult. Even when loaded in the surface direction of the base body and in particular also of the cover body, a deformation counteracting a loosening of the connection is advantageously enabled. Such a load can occur, for example, due to different thermal expansions of the cover body and the base body and / or due to centrifugal forces during rotation.

[0014] "Microfluidic" is understood in particular to mean a structure that is designed and intended to guide a fluid and whose smallest spatial extent (e.g. the width and / or depth of a channel or chamber) is in the range of less than one millimeter

[0015] Particularly preferably, the base leg and the free leg are at an angle greater than zero and less than 90 degrees (preferably less than 60, more preferably less than 45 degrees) to one another. When viewed along the surface of the base body or cover body, this results in at least an imaginary triangle, which is open in particular at one leg (the free leg). If the open leg of the triangle is then loaded, the base leg connected to it also shifts. Due to this mechanical interlinking, at least under load, there is an advantageous spreading of the locking hook in the holding opening, which can actually increase the locking effect rather than reduce it or even lead to it becoming loose.

[0016] Optionally, the locking hook (or the respective locking hook) is aligned with its "triangular plane," i.e., the plane spanned by the base and free leg, in an expected load direction, particularly in the direction of centrifugal force. This results in, at least in most cases, a load on the locking hook, which leads to a deflection of the free leg toward the base leg (or vice versa). Due to the above-mentioned linkage of these two legs, the locking effect is actually enhanced, for example, since such a deflection can lead to tension between the two legs. Alternatively, several locking hooks are available, each positioned at a different angle relative to the direction of centrifugal force.

[0017] In a practical embodiment, the (or the respective) holding opening has a contact surface against which the foot shank at least partially rests with its back side (facing away from the free shank). Alternatively, the back side can also be a slight distance from the contact surface. A slight distance is understood here to be a distance value that is small in relation to the thickness (i.e. the cross-section) of the locking hook, the spring travel or the like. This slight distance therefore represents in particular a slight play of the locking hook in the holding opening. Due to the contact or the slight distance, even slight movements of the cover body and the base body relative to one another can advantageously lead to deformation and thus advantageously to additional spreading of the locking hook in the holding opening.

[0018] In another practical embodiment, a contact projection (also referred to as a "nose") protrudes from the back of the locking hook, preferably at the transition from the base to the middle section. This nose is designed in such a way that the back is "extended" (particularly compared to an imaginary or "ideal" curve of the middle section) and optionally also protrudes toward the contact surface in the area of ​​the nose. This allows the locking hook to be even better supported on the contact surface and, in particular, to wedge itself into place when subjected to load in the direction of disassembly.

[0019] In an optional embodiment, the locking hook also has a hump on its back side that protrudes towards the outside. This hump thus forms a wave-like elevation on the back side. The wavelength is short compared to the length of the base leg, for example, many times smaller (e.g., 3 or 5 times). This hump serves in particular as a demolding aid for the preferably injection-molded production of the cover body. The hump advantageously prevents premature demolding of the locking hook, which could lead to undesirable deformation. Furthermore, the hump can advantageously initiate contact between the contact surface and the locking hook. Optionally, contact between the hump and the contact surface already exists in the intended assembly state, not subject to external influences.

[0020] In a preferred embodiment, the locking hook rests with its locking surface against a locking shoulder. This locking shoulder protrudes into the retaining opening, in particular from a locking side of the retaining opening opposite the contact surface.

[0021] Preferably, the respective locking hook(s) is clamped in the retaining opening in the intended, unloaded assembly state. In particular, the locking hook rests on the front and rear sides (i.e., with its locking surface) against the contact surface or locking shoulder of the retaining opening and is at least slightly elastically deformed. As a result, even a slight displacement of the cover body relative to the base body can lead to the deflection of the locking hook described above. Rattling of the cover body due to a loose fit can thus be effectively prevented, creating a high-quality impression.

[0022] In a practical embodiment, the respective holding opening is formed in a holding dome protruding from the base body or the cover body in the direction of the corresponding other component. This is particularly useful in cases where both the base body and the cover body have comparatively thin walls, but a predetermined distance must be maintained between the two. The holding dome can, for example, function as a spacer. Preferably, the locking shoulder described above is formed at the end facing the opposite component. This allows the U-shaped middle section of the locking hook to remain within the holding dome without protruding on the opposite (rear) side of the base body or the cover body. This allows this side of the base body or the cover body to be provided with an adhesive sticker, e.g. a label, or the like, without causing it to bulge.

[0023] In an expedient further development, the cover body or the base body (in any case the body which also has the locking hook) has at least one, in particular rib-like, projection. This is preferably assigned to one of the possibly several locking hooks and arranged adjacent to it. The projection engages - in the intended assembled state - on the outside for centering on the retaining dome, i.e. rests against the retaining dome. The projection serves as an insertion aid (for the locking hook into the holding opening) and / or as a displacement barrier during operation. In the latter case, the projection resting against the retaining dome reduces or prevents displacement of the retaining dome towards the locking hook. In the event that the

[0024] If the base body or the cover body has a plurality of holding openings and the cover body or the base body, conversely, has a plurality of latching hooks, a plurality of projections assigned to the respective latching hooks can particularly effectively prevent a displacement of the cover body relative to the base body (particularly in the case of differently aligned contact standards between the holding domes and the projections).

[0025] In a preferred embodiment, the (process) chamber covered by the cover body is an amplification chamber, in particular a so-called pre-amplification chamber, for the replication of genetic material. In such a pre-amplification chamber, the genetic material contained in a sample is amplified in order to have a sufficient amount of genetic material available for various testing procedures (e.g., further amplifications) or for a statistically sufficiently reliable investigation in a subsequent process step.

[0026] In a practical embodiment, the cover body completely covers the upper side of the base body at least approximately (i.e. in particular all chambers and channels).

[0027] In an advantageous embodiment, the cover body has a frame web that protrudes toward the top side of the base body and surrounds the covered chamber, in particular the aforementioned amplification chamber. This prevents or largely reduces convection parallel to the surface of the base body, in particular an air flow running between the surface of the base body and the cover body, at least across the chamber to be covered, preferably the aforementioned (pre-)amplification chamber. This allows for particularly high temperature homogeneity (or, in other words, a particularly small temperature deviation) to be achieved within the chamber (in a "quasi-stationary" state, especially after a comparatively long holding time of the process parameters, i.e., heating temperature and rotation speed, of, for example, 30 seconds or more).In particular, temperature differences of less than 10 Kelvin, preferably less than 5, in particular of about 2 Kelvin can be achieved.

[0028] The base body of the cartridge is preferably formed from a substrate, in particular a thermoplastic substrate, into which the channel and chamber structure is formed, and a sealing layer, in particular a sealing film, which is firmly connected to the substrate after a sealing step and thus closes the channel and chamber structure.

[0029] In a further preferred embodiment, the base body is made of a cycloolefin copolymer (COC), and the cover body is made of another, particularly thermoplastic, plastic, preferably polypropylene (PP). The locking hook is preferably formed on the cover body, since its material has more favorable deformability properties than that of the base body.

[0030] The conjunction "and / or" is to be understood here and in the following in particular in such a way that the features linked by means of this conjunction can be formed both together and as alternatives to one another.

[0031] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. In the drawings: Fig. 1 in a schematic exploded view a cartridge for use in a rotation-based analysis method, Fig. 2 in a schematic plan view of a heat input side of a base body of the cartridge, Fig. 3 in a schematic view of a bottom side of a cover body of the cartridge, Fig. 4 in a perspective partial sectional view, a partial and schematic view of a connection point between the base body and the cover body, Fig. 5, 6 in a partial sectional view, a partial and schematic view of the connection point of two different embodiments, and Fig. 7, 8 in view according to Fig. 5 each schematically shows an unassembled and an assembled state of the base body and cover body.

[0032] Corresponding parts are always provided with the same reference symbols in all figures.

[0033] In Fig. 1 A schematic representation of a sample container referred to as a "cartridge" – or, due to its flat geometry resembling a halved circular disk, also referred to as "disk 1" for short. This disk 1 is used in a rotation-based analysis method. The disk 1 has a base body 2 (also referred to as a "substrate") that has a microfluidic channel and chamber structure 4. This channel and chamber structure 4, in turn, has several chambers 6, described in more detail below, which are interconnected by means of associated channels 8 (cf. Fig. 2 ). In the unassembled state, the chambers 6 and channels 8 each form "exposed", basin- or groove-like depressions in the base body 2. The disk 1 therefore also has a sealing film 10 (or "sealing layer"), which is heat-sealed to the microfluidic base body 2 and thus closes the channel and chamber structure 4 from a side referred to below as the "heat input side 12" (see Fig. 1 ). The base body 2 has a lateral access 14 to the channel and chamber structure 4, through which sample material can be introduced into the channel and chamber structure 4. This access 14 can be reversibly closed by means of a cap 16 (here specifically a screw cap) to enable the introduction of the sample material and subsequent reclosure. The disk 1 also has a cover body, referred to below as "cover 18", which is placed on a "top side 20" (or "back side" to the heat input side 12) on the base body 2 and, in the present embodiment, by means of (in Fig. 1 only hinted at, in Fig. 4-8 shown in detail) locking hooks 22 in corresponding holding openings 24 of the base body 2. The cover 18 has a first and a second reading window 26 and 28, respectively, through which the contents of the underlying chambers 6 of the

[0034] base body 2 and can thus be analyzed (e.g. by means of fluorescence detection) or at least controlled.

[0035] In an optional variant (shown here), the disk 1 also has a (here two-part, preferably self-adhesive) label 30 applied to the cover 18. The label 30 is designed to enable reading through the readout windows 26 and 28. In an optional development of this variant, the label 30 has transparent areas that cover the readout windows 26 and 28. These transparent areas are expediently not provided with adhesive - i.e., are left free of adhesive - so that the fluorescence detection is not influenced by any luminescent adhesive.

[0036] In the cover 18, recesses 32 are formed laterally in a side wall 34, which enable alignment and positioning of the disk 1 in an automatic feeder of an analysis device.

[0037] The base body 2 has several (here specifically two) openings 36, which serve to precisely align and position the disk 1 on a support plate (hereinafter referred to as the "rotary plate") of the analyzer. Positioning pins of the rotary plate engage in these openings 36 for positioning and fixing in a rotation plane that is parallel to the surface of the rotary plate and the heat input side 12 (and thus to the planar extension) of the disk 1.

[0038] The analyzer's turntable is used for centrifugation, i.e., for rotating disk 1 around a rotation axis. The turntable is designed to accommodate two disks 1 and is therefore 180 degrees symmetrical (see Fig. 3 ). In addition, the turntable carries several heating elements that serve to locally heat individual chambers 6 of the channel and chamber structure 4 of the disk 1 and are therefore adapted in their outer contour to the corresponding chambers 6. In this case, the heating elements are formed by resistance heating plates.

[0039] To further reduce the heat dissipation, the cover 18 in a further embodiment has a frame web 38 which surrounds the pre-amplification chambers 56 in a ring-like manner and thus further reduces the heat dissipation by convection on the upper side 20 (see Fig. 1 and 3). The frame web 38 is formed onto the cover 18, i.e., is integrally connected thereto. The frame web 38 projects in the direction of the base body 2 and ends at a small distance of approximately 100 µm from the base body 2. The frame web 38 encloses two chambers 6 serving as pre-amplification chambers 40. This continued shielding of the pre-amplification chambers 40 by the cover 18 and the frame web 38 enables a temperature difference of approximately 2 Kelvin within the respective pre-amplification chamber 40. Thus, comparatively strong convection occurs in the respective pre-amplification chamber 40, due, among other things, to the rotation. In addition, a comparatively high homogeneity of the reaction temperature within the pre-amplification chamber 40 is achieved - at least in the static case, ie when the temperature of the heating element is maintained for at least about 10 to 30 seconds.Experience has shown that with the geometry described here and below and the parameters used, static conditions arise after only about 15 seconds.

[0040] Even in the event that a reaction takes place in the pre-amplification chambers 40 which requires an interaction, for example a binding of molecules to a solid phase, e.g. to microarrays, or a reaction in which the concentration of the respective reaction partners is usually low and therefore contact between the respective reaction partners is subject to a comparatively low probability, the high convection (and thus comparatively strong mixing) as well as the homogeneous temperature distribution can be advantageous.

[0041] The locking hook 22 and the holding opening 24 are in Fig. 4 bis 6 shown in more detail. The locking hook 22 is basically U-shaped. Specifically, the locking hook 22 has a straight, elongated (i.e. long compared to its thickness and / or width) base leg 50. This base leg 50 is based on the cover 18 (i.e. is connected to the cover 18) and protrudes from it slightly tilted against a surface normal, i.e. at an angle of less than 90 degrees but greater than 60 degrees, preferably greater than 70 degrees, in the direction of the base body 2. The locking hook 22 also has a U-shaped bent middle part 52 and a (straight, elongated) free leg 54. The foot leg 50 merges into the middle part 52 and this in turn into the free leg 54. The latter ends with a free end 56 (i.e. without connection to another component). The foot leg 50 and the free leg 54 form an angle of approximately 5 to 20 degrees, specifically between 7 and 12 degrees.At the free end, the locking hook has a shoulder 58, on which a locking surface 60 pointing towards the free end 56 and thus back to the cover 18 (see . Fig. 7-8 ) is trained.

[0042] In Fig. 4-6 and 8 In the intended assembly state shown, the locking hook 22 rests against a locking shoulder 62 of the holding opening 24 to form the locking connection with this locking surface 60. Furthermore, the locking hook 22 extends through the holding opening 24 (at least its cover-side "mouth") with the central part 52. To mount the cover 18 on the base body 2, the free leg 54 and the foot leg 50 must therefore be bent towards each other.

[0043] The retaining opening 24 is formed within a projection of the base body 2 designed as a kind of tower or "dome" (referred to here as the "retaining dome 64"). The locking shoulder 62 protrudes into the cover-side "mouth" of the retaining opening 24 in a limiting manner. The retaining dome 64 and the locking hook 22 are dimensioned such that the locking hook 22 does not protrude from the rear of the retaining opening 24 and thus from the retaining dome 64. The "clear width" of the cover-side mouth of the retaining opening 24 is dimensioned such that the above-mentioned bending of the locking hook 22 remains within the elastic deformation range during assembly.

[0044] The retaining opening 24 also has a contact surface 66 arranged opposite the locking shoulder 62. This contact surface 66 is inclined as a type of insertion bevel, widening the retaining opening 24 toward the cover-side opening. Furthermore, the contact surface 66 also serves as a type of abutment for the locking hook 22, which, in the intended assembly state, rests against the base leg 50 with a back side 68.

[0045] In the illustrated embodiments, a hump 70 is formed on the back side 68 of the foot leg 50. This hump serves as a demolding aid during the production of the cover 18 in a plastic injection molding process, specifically as a type of retainer that prevents the locking hook 22 from being demolded "prematurely" and undesirably deformed during an adjustment of a movable mold core.

[0046] In the illustrated embodiments, the locking hook 22 is in the intended, unloaded assembly state (see Fig. 4 and 6 ) in the holding opening 24, i.e. between the locking shoulder 62 and the contact surface 66. In principle, however, there may also be a slight play with the contact surface 66.

[0047] In the embodiment according to Fig. 7 und 8 The locking hook 22 is smooth on the outside in the area of ​​the middle part 52. In the Fig. 4-6 In the embodiments shown, the locking hook 22 has a "nose" 72 on its back side 68 at the transition from the foot leg 50 to the middle part 52, which defines the area (or "length") of the back side 68 in the longitudinal direction of the locking hook 22 (compared to Fig. 7 und 8 ) is extended. This nose 72 has the effect, when the locking hook 22 is pulled out of the holding opening 24 without the locking surface 60 being "decoupled" from the locking shoulder 62, that the locking hook 22 rests against the contact surface 66 for a longer time and thus the locking hook 22 can "wedge" itself comparatively strongly.

[0048] Due to the geometry of the locking hook 22 described here, a displacement of the cover 18 relative to the base body 2 in the direction of the plane spanned by the foot leg 50 and the free leg 54 (in Fig. 5-8 i.e., the plane of the drawing) leads to further tensioning of the locking hook 22 in the holding opening, which even reinforces the locking effect of the locking surface 60 on the locking shoulder 62. This effectively prevents unintentional release of this locking connection during operation of the analyzer, i.e., under the influence of increased temperature and centrifugal force.

[0049] Out of Fig. 6 A further embodiment can be seen. Here, the cover 18 has at least one projection locally next to at least some locking hooks 22 - referred to here as a "guide rib 74". This guide rib 74 is adjacent to the respective locking hook 22 and points in the same direction. Furthermore, the respective guide rib 74 is aligned such that its longitudinal extent is aligned, at least approximately, normal to the outside of the respective holding dome 64. (see also Fig. 3 ). The guide ribs 74 serve both as a centering device, e.g., as an insertion aid, in order to be able to insert the respective locking hook 22 into the holding opening 24 of the corresponding holding dome 64 with as little jamming as possible. In the assembled state (see Fig. 6 ) the respective guide rib 74 serves - due to its contact with the holding dome 64 or its slight distance from it (cf. Fig. 6) - as an obstacle or stop against displacement of the cover 18 relative to the base body 2.

[0050] The subject matter of the invention is not limited to the embodiments described above. Rather, further embodiments of the invention can be derived by those skilled in the art from the above description, provided they do not deviate from the subject matter of the appended claims. List of reference symbols

[0051] 1Disk 2Base body 4Channel and chamber structure 6Channel 8Channel 10Sealing foil 12Heat input side 14Access 16Cap 18Cover 20Top 22Locking hook 24Holding opening 26Reading window 27Reading window 30Label 32Recess 34Side wall 36Opening 38Frame web 40Pre-amplification chamber 50Foot leg 52Middle section 54Free leg 56Free end 58Step 60Locking surface 62Locking shoulder 64Holding dome 66Contact surface 68Back side 70Hump 72Nose 74Guide rib

Claims

1. A cartridge (1) for a rotation-based analysis method which utilizes heat input, having - a basic body (2) which extends in a planar manner, in which a channel and chamber structure (4) is formed, - a cover body (18) attached to the basic body (2), which on one side is arranged on an upper side (20) of the basic body (2) facing away from a heat input side (12) and covers at least one chamber (6, 40) of the basic body (2), wherein the basic body (2) and / or the cover body (18) have / has a number of holding openings (24), wherein the cover body (18) or the basic body (2) has a number of latching hooks (22) each assigned to one of the potentially multiple holding openings (24), wherein the latching hook (22) with a foot limb (50) protrudes from the cover body (18) or the basic body (2) toward the basic body (2) or the cover body (18), wherein the foot limb (50) transitions to a central part (52) bent in a U shape, which itself then transitions to a free limb (54), which is directed back toward the cover body (18) or the basic body (2) and is terminated with a free end (56), wherein the latching hook or each latching hook (22) on the free-end side has a ledge (58) with a latching surface (60), which is directed toward the free end (56), and wherein the latching hook or each latching (22) extends through the assigned holding opening (24) with its central part (52) bent in a U shape, forming the latching connection.

2. The cartridge (1) as claimed in claim 1, wherein the holding opening or each holding opening (24) has a contact surface (66) on which the rear side (68) of the foot limb (50) at least partially rests, or from which the rear side (68) is spaced slightly apart.

3. The cartridge (1) as claimed in claim 2, wherein a contact projection (72) protrudes on the rear side (68) of the latching hook or each latching hook (22), preferably at the transition from the foot limb (50) to the central part (52).

4. The cartridge (1) as claimed in one of claims 1 to 3, wherein the latching hook (22) with its latching surface (60) rests on a latching shoulder (62) projecting into the holding opening (24), in particular on a latching side opposite the contact surface (66).

5. The cartridge (1) as claimed in one of claims 1 to 4, wherein the latching hook or each latching hook (22) is tensioned in the holding opening (24).

6. The cartridge (1) as claimed in one of claims 1 to 5, wherein the holding opening or each holding opening (24) is formed in a retaining spike (64) protruding from the basic body (2) or the cover body (18) toward the respective other element (18, 2).

7. The cartridge (1) as claimed in claim 6, wherein the cover body (18) or the basic body (2) has at least one projection (74) which engages on the retaining spike (64) on the outside for centering.

8. The cartridge (1) as claimed in one of claims 1 to 7, wherein the chamber covered by the cover body (18) is an amplification chamber (40) for replicating DNA.

9. The cartridge (1) as claimed in one of claims 1 to 8, wherein the cover body (18) has a frame stay (38) protruding toward the upper side (20) of the basic body (2) and surrounding the covered chamber (6, 40).

10. The cartridge (1) as claimed in one of claims 1 to 9, wherein the basic body (2) comprises an, in particular thermoplastic, substrate with a channel and chamber structure (4) incorporated into it and a sealing layer (10) which is used to seal the channel and chamber structure (4).

11. The cartridge (1) as claimed in one of claims 1 to 10, wherein the basic body (2) is made from a cyclic olefin copolymer and the cover body (18) from a different, in particular thermoplastic, synthetic material, in particular a polypropylene.

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