Tray for a cuvette matrix

Abstract: The invention concerns a tray (6) for a cuvette matrix (1). The tray comprises at least one aperture matrix corresponding to said cuvette matrix (1), with an aperture (8) for each cuvette (2) of the matrix (1). The aperture comprising a flexible clamping element (9) keeping said cuvette in place by means of friction.The clamping element includes at least one flexible finger (9) placed on a wall of the aperture (8) that presses the cuvette (2) against the other wall (10) of the aperture (8).

Description: This invention concerns a tray for a cuvette matrix formed by rows. If necessary, smaller parts of the matrix can be removed and put back into the tray. The cuvette matrix is especially suitable for use in different diagnostic measurements, f.e. for EIA-assays. Cuvette matrices can f.ex. form a so called microtitration plate. Generally used for diagnostic assays are test plates formed by rows of cuvettes, f.ex. the so called microtitration plate into the cuvettes of which the samples are placed. Mostly used is a standard plate with 8 x 12 cuvettes with a distribution of 9 mm. Known are also cuvette sets, a smaller part of which can be removed, if ncessary. Thus, it is not necessary to use the whole set, if there are only a few of the samples. US-A-4,154,795 dicloses a microtitration plate the wells (cuvettes) of which have been connected with one another by rigid, straight stems right by the well row. The stems can be broken and in this way it is possible to remove a necessary amount of wells from the plate. The tray of the plate is equipped with posts placed in spaces between the wells. One problem with this solution is the fact that the wells do not stand upright in the tray properly, when the tray is moved. F.ex. during stages of washing it is often necessary to turn the tray upside down, whereby the wells tend to fall down. Even the fact that the different wells are at different heights in the tray can cause difficulties with the measuring device. GB-A-2 064 998 discloses to a rack for centrifuge tubes comprising recesses for a plurality of tubes formed by vertically stackable members, wherein said members include cut-outs which contain elastic securing elements which fill a part of the space of the recesses for the tubes, and wherein the tubes themselves are held fast by the gripping action of said elastic elements. In particular, the elastic securing elements are formed of star-shaped rubber plates which are located in the corners of the recesses for the tubes. When the tubes are inserted into the recesses, the tips of the stars come into contact with the tubes and are deformed within the space between the tubes and the corners of the recesses. The present invention provides a tray with space for at least one cuvette matrix having at least one line or row of cuvettes, said tray comprising at least one aperture matrix corresponding to said cuvette matrix, with an aperture for each cuvette of the matrix, said apertures forming rows and columns delimited by a frame with integral separation walls, the separation walls being parallel with the columns being rigid, and every second wall separating the rows being vertically cut off at the centre line of the column, forming a gap between the cut-off ends to form a flexible clamping element comprising at least one flexible finger for pressing the cuvette against the rigid frame and keeping the cuvette in the aperture with the help of friction. In drawings of the detailed description of the invention, figures 1a and 1b show one row-formed cuvette matrix viewed from side and above, figures 2a and 2b show one cuvette matrix tray in accordance with the invention, viewed from side and above, and figures 3a and 3b show a detail of the tray in accordance with figures 2a and 2b, where the matrix in accordance with figures 1a and 1b and one of its cuvettes has been placed in, viewed from side and above. The cuvette matrix is formed by straight rows of cuvettes, with one of them or several side by side. The matrix is advantageously made of some suitable plastic material by injection-moulding. The cuvettes are preferably cylindric cups. For optical measurements, if necessary, their bottom is transparent. The matrices are suitable for use especially in different diagnostic assays on fluid samples, f.ex. in EIA assays. If necessary, the cuvettes can be pretreated, f.ex. the content can be coated with antigen of the antibody to be assayed. At least a part of adjacent cuvettes of the matrix have been connected with one another by flexible connecting elements and are preferably connected with one another in a way that a desired amount of cuvettes can readily be removed from the matrix. The removability is preferably attained by making the connecting elements to be readily breakable. The tray is formed by a frame with an aperture at least for one cuvette of the matrix. The aperture includes a flexible clamping element that fastens the cuvette into the aperture with the help of friction, preferably by pressing its lower part from sides. The clamping element, anyway, gives that much way that the cuvette can be pushed into the aperture. The clamping element may press the cuvette from one side or several sides. According to one embodiment the clamping element presses the cuvette against a rigid frame. The clamping element is formed by one or more flexible fingers. The finger is preferably flexible horizontally. Enclosed figures 1 - 4 describe one application of the invention adapted to a micro test plate 8 x 12. Figures 1a and 1b describe a one-row cuvette matrix 1. The single cuvettes, i.e. wells 2 thereof have been connected with one another by narrow stems 3. The stems 3 are fixed to the top part of the wells. The stems 3 are placed at a distance from the centre line of the cuvette row at sides of the cuvette row, so that the stems 3 next to each other are each in opposite sides. The stems 3 give that much way that each distance between adjacent wells 2 can get smaller and wider for some hundredths or tenths of a millimeter. The inside of the wells 2 is cylindric. Their bottom forms a light transmission measuring window. The window is protected against scratching with a collar around the window. On the outer surface of the wells 2, slightly below the middle there is a shoulder 5, broader than the lower part of the well, which determines how deep the well can be pushed into the tray 6. The outer surface of the lower part of the well 2 is cone-shaped, tapered slightly downwards. The stems 3 can be broken by hand. This enables the required amount of wells 2 to be readily removed. In both ends of the cuvette matrix there are flanges 7 at the top part, that can also be broken off. In the tray 6, in accordance with figures 2a and 2b, there are 8 x 12 apertures 8, in cross-sectional shape quadratic. The side of the aperture 8 is slightly shorter than the biggest diameter of the lower part of the well 2. The apertures 8 form 8 rows, marked with letters (A - H) and 12 columns, marked with numbers (1 - 12). The apertures 8 are delimited by a rectangular frame with separation walls perpendicular to one another. Separation walls parallel with the columns are integral and rigid. From the second separation wall on, from the side, every other wall parallel with the rows is also integral and rigid. From the first separation wall, from the side, every other wall parallel with the rows is cut off vertically at the centre line of the column, but diagonally against the separation wall and so that there is a small gap between the cut-off ends. The thus formed fingers 9, parallel with the separation walls of the rows, are slightly bent in horizontal direction. Thus, a well 2 can be pushed into each aperture 8, whereby the finger 9 bends away from the centre of the aperture. The finger 9 still keeps the well 2 in the aperture with the help of friction. The upper edge of the rigid separation walls 10 stops the shoulder 5 on the outer surface of the well 2. Also on the sides of the tray the frame has ancons against the shoulders 5. On the side of the tray there is a pin 11 at the lower end of each column. One head flange 7 of the cuvette-matrix has a corresponding hole 12. Thus, the cuvette matrix is always put the right way on the tray. Lower edges of the tray extend lower than the bottoms of the wells 2 in the tray. Additionally, there are lips in the corners 13 of the tray to enable the trays to be readily piled.

Claims: A tray with space for at least one cuvette matrix having at least one line or row of cuvettes (2), said tray comprising at least one aperture matrix corresponding to said cuvette matrix, with an aperture (8) for each cuvette of the matrix, said apertures forming rows and columns, characterised in that said apertures are delimited by a frame (6) with integral separation walls (9, 10), the separation walls parallel with the columns being rigid, and every second wall separating the rows being vertically cut off at the centre line of the column, forming a gap between the cut-off ends to form a flexible clamping element comprising at least one flexible finger for pressing the cuvette (2) against the rigid frame and keeping the cuvette in the aperture (8) with the help of friction. The tray as claimed in claim 1, characterized in that there is only one finger (9) for each cuvette (2). The tray as claimed in any one of claims 1 or 2, characterized in that the aperture (8) is quadratic in cross-section.

Inventors: TERVAMAEKI JUKKA, VAURAMO KARI, TERVAMAEKI, JUKKA, VAURAMO, KARI, TERVAMÄKI, Jukka
Applicants: LABSYSTEMS OY
Application year: 1990
Main classification: B01L9
IPC codes: B01L3, B01L9