GB1584589A - Microtitration plate - Google Patents

Description

(54) MICROTITRATION PLATE (71) We, DYNATECH HOLDINGS LIMITED, a Guernsey Company of Abacus Chambers, Smith Street, St.Peter Port, Guernsey, Channel Islands, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is performed to be particularly described in and by the following statement: This invention relates to laboratory apparatus for use in the conducting of body fluid investigations such as complement fixation tests, hemagglutinition tests, hemagglutinition inhibition tests and metabolic inhibition tests and immuno chemical and both isotopic and non-isotopic immuno assays. More particularly, the invention relates to a microtitration or microtest plate.

In known microtitration plates, the wells, cups or recesses for receiving samples of a body fluid to be tested are formed by drilling or moulding. For example, U.S.

Patent Specification No. 3,356,462 discloses a moulded microtitration plate made of a transparent rigid synthetic plastics material and having twelve rows of integral open-top wells or cups, eight in each row. The main disadvantage of such microtitration plates is their lack of versality.

An object of the present invention is to provide a microtitration plate which has a greater degree of versatility than the known microtitration plates referred to above.

To this end, the invention consists in a microtitration plate comprising a tray formed as a one piece moulding and having a multiplicity of compartments arranged in one or more rows on the tray, and a multiplicity of individual wells, each well being supported in an upright position in a compartment.

One advantage of the invention resides in the fact that the individual wells can be pretreated with different test materials for testing different diseases in any desired combination in one tray since the pretreatment can be carried out before the wells are fitted into the tray. For example, the wells can be pretreated with a wetting agent or processed to enable them to grow cell cultures. In another example, they may be pretreated with different concentrated antigen, antibody, or antibiotic test materials, as well as with radio-isotopes for use in radio-immuno-assay and enzyme linked test materials for use in enzyme linked immunosorbent assays for the determination of the antigen or antibody content of body fluids.

The pretreated wells can then be processed, for example by freeze drying the test material, and the processed wells fitted into the tray compartments in the desired combination. When fitted into the tray, the individual wells can easily be covered or sealed by any suitable means. Thus, a single tray can be used to perform a variety of tests on a body fluid sample from a single patient.

Preferably, the bottoms of the compartments of the tray have apertures extending through the tray bottom. Thus, when the wells are provided with optical quality flat bases, as is preferred, optical and colour readings may be taken of the samples in these wells through the bottom of the tray so that the samples do not have to be removed from the wells for analysis by optical or colorimetry techniques. Moreover, the apertures in the compartment bottoms enable the wells to be readily removed individually from the tray merely by applying a push through the apertures.

Alternatively, the wells may be removed from the top of the tray by means of tweezers, for example, when the tray has no apertures, and to assist in such removal the tops of the wells conveniently project beyond the upper surface of the tray.

In a preferred embodiment of the invention including a plurality of rows of the compartments, the compartments are de fined by rows and columns of posts integrally moulded with the tray within a recess in the tray. Such a construction readily lends itself to moulding techniques. Conveniently, the outermost posts are half posts which are moulded integrally with the side walls of the tray recess and the inner posts are prefer -ably of lesser height than the outermost posts and the adjacent upper surface of the tray.

The wells may be sealed by an adhesive cover strip or individual plugs. Preferably, the adhesive cover strip has perforations around the wells so that the wells remain sealed when the cover strip is removed and can be individually opened as required. A similar advantage can be achieved if the plugs are carried by a cover strip having perforations around the plugs. The cover strip is conveniently made from sterilizable polyester adhesive sealing tape.

Instead of or in addition to the sealing strip or plugs the microtitration plate may comprise a lid which fits into a peripheral rebate on the tray and clears the tops of the wells.

The wells are conveniently made of a material having an affinity for molecules of the body fluid sample or material with which the sample may be mixed for testing and analysis. For example, the walls may be made of rigid PVC or polystyrene which have the advantage of having an ability to attract protein molecules but any other suitable plastics material which has an affin ity for sample or test molecules may be used.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of one form of tray forming one part of a microtitration plate constructed in accordance with the inven tion, Figures 2 and 3 are side and underneath plan views respectively of the tray of Figure 1, Figure 4 is a cross-section on the line A-A of Figure 1 looking in the direction of the arrows, Figure 5 is a fragmentary perspective view of the tray of Figure 1 showing the manner in which one of a multiplicity of individual wells forming the other part of the plate is fitted into the tray, Figure 6 is a cross-section showing the tray with a lid thereon, Figures 7 and 8 are plan and side views respectively of the microtitration plate showing the wells fitted in the tray, Figure 9 is a cross-section on the line B-B of Figure 7, Figure 10 is a cross-section on the line C-C of Figure 7, showing one shape of well base, Figure 11 is a side view of the tray of Figure 7 with the lid thereon, Figures 12 and 13 are views similar to that of Figure 10 but showing two further.shapes of well base, Figure 14 is a side view of the tray of Figure 7 showing the tray with a cover strip instead of a lid, and Figure 15 is a fragmentary plan view of a modified form of tray.

Referring to Figures 1 to 6, there is shown a tray 1 moulded from polystyrene foam and having a tray recess 2, upper surface 3 and an undersurface 8. The tray recess 2 has a multiplicity of compartments 4 arranged in twelve rows with eight compartments in each row and defined by rows and columns of posts upstanding from the base of the recess. The compartments 4 are fitted with a multiplicity of individual rigid, or separate, microtitration tubes or wells, of which one well 5 is shown in Figure 5, for receiving a sample of a patient's body fluid to be tested, the sample usually being mixed with test material in the wells. The outermost posts 6a are half posts which are moulded integrally with the side walls 6 of the recess 2 and extend to the height of the recess to be flush with the upper surface 3 of the tray, whereas the inner posts 6b are of lesser height than the outer posts 6a.

The bottom of each compartment 4 has an aperture 7 extending through the tray bottom to enable optical or colour readings to be taken of the sample in the well 5 without removing the well from the tray and to permit the wells to be pushed from the compartments. The upper surface 3 of the tray has a peripheral rebate 9 into which fits a lid 10 (Figure 6) which covers the compartments 4 and surface 3. The tray 1 also has a rebate 11 in its undersurface 8 so that the under surface 8 can fit into a depression 12 in the upper surface of the lid 10 with the rebate 11 engaging a lip 13 of the lid of a similar tray for stacking one tray upon the other.

As will be apparent from Figures 7 to 9, the wells 5 are supported in the compartments 4 in an upright position with their cylindrical outer surfaces engaging the four posts defining the respective compartments.

The wells which are of rigid transparent PVC or polystyrene have a frusto-conical top inner edge portion as indicated at 18 in Figure 5 and project beyond the upper surface 3 of the plate 1 to facilitate removal of the individual wells with tweezers from the top of the tray. As shown in Figure 10 each well 5 has a flat optical quality base 14.

Instead of or in addition to the lid 10 which, as shown in Figure 11, clears the tops of the wells, an adhesive sealing cover strip 15 may be applied to the tops of the wells 5 to seal them, as shown in Figure 14, conveniently with perforations around the individual wells.

The shape of the bases of the wells may be conical as indicated at 16 in Figure 12 or hemispherical as indicated at 17 in Figure 13 instead of flat or any combination of wells with such bases may be fitted in the tray compartments.

In the modification shown in Figure 15, the apertures 7 are omitted from the bottoms of the compartments 4 of tray 1.

Various modifications may be made without departing from the scope of the invention as defined by the appended claims. For example, the tray may be moulded from flexible silicone rubber instead of foam plastics, to facilitate removal of the wells.

The wells may be made of glass instead of a plastics material. Moreover, the wells may be of different heights and the tops of the wells may be flush with the upper surface 3 of the tray in which case the lower posts 6b will facilitate the removal of the wells by means of tweezers from the top of the tray.

WHAT WE CLAIM IS: 1. A microtitration plate comprising a tray formed as a one piece moulding and having a multiplicity of compartments arranged in one or more rows on the tray, and a multiplicity of individual wells, each well being supported in an upright position in a compartment.

2. A microtitration plate as claimed in claim 1, including a plurality of rows of the compartments defined by rows and columns of posts integrally moulded with the tray.

3. A microtitration plate as claimed in claim 2, wherein the posts are situated in a recess in the tray.

4. A microtitration plate as claimed in claim 3, wherein the outermost posts are half-posts moulded integrally with the side walls of the tray recess, and the inner posts are of lesser height than the outermost posts and the adjacent upper surface of the tray.

5. A microtitration plate as claimed in any one of the preceding claims, wherein the bottoms of the compartments have apertures extending through the tray bottom.

6. A microtitration plate as claimed in any one of the preceding claims, wherein the wells have flat optical quality bases, conical bases or part-spherical bases.

7. A microtitration plate as claimed in any one of the preceding claims, wherein the tops of the wells project above the upper surface of the tray.

8. A microtitration plate as claimed in any one of the preceding claims, wherein the tray is moulded from foam plastics material or silicone rubber.

9. A microtitration plate as claimed in any one of the preceding claims, wherein the tray has a peripheral rebate and a lid fits into the rebate and clears the tops of the wells.

10. A microtitration plate as claimed in any one of the preceding claims, wherein the wells are sealed by an adhesive cover strip.

11. A microtitration plate as claimed in any one of the preceding claims 1 to 9, wherein the wells are sealed by plugs carried by a cover strip.

12. A microtitration plate as claimed in claim 8 or 9, wherein the cover strip is perforated about the individual wells to facilitate selective opening of the wells.

13. A microtitration plate substantially as hereinbefore described with reference to Figures 1 to 5, and 7 to 10 of the accompanying drawings.

14. A microtitration plate substantially as hereinbefore described with reference to Figures 6 and 11 of the accompanying drawings.

15. A microtitration plate substantially as hereinbefore described with reference to Figure 14 of the accompanying drawings.

16. A microtitration plate substantially as hereinbefore described with reference to Figure 15 of the accompanying drawings.

17. A microtitration plate as claimed in claim 14, 15 or 15 and modified substantially as hereinbefore described with reference to either Figure 12 or Figure 13 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (17)

**WARNING** start of CLMS field may overlap end of DESC **. individual wells. The shape of the bases of the wells may be conical as indicated at 16 in Figure 12 or hemispherical as indicated at 17 in Figure 13 instead of flat or any combination of wells with such bases may be fitted in the tray compartments. In the modification shown in Figure 15, the apertures 7 are omitted from the bottoms of the compartments 4 of tray 1. Various modifications may be made without departing from the scope of the invention as defined by the appended claims. For example, the tray may be moulded from flexible silicone rubber instead of foam plastics, to facilitate removal of the wells. The wells may be made of glass instead of a plastics material. Moreover, the wells may be of different heights and the tops of the wells may be flush with the upper surface 3 of the tray in which case the lower posts 6b will facilitate the removal of the wells by means of tweezers from the top of the tray. WHAT WE CLAIM IS:

1. A microtitration plate comprising a tray formed as a one piece moulding and having a multiplicity of compartments arranged in one or more rows on the tray, and a multiplicity of individual wells, each well being supported in an upright position in a compartment.

2. A microtitration plate as claimed in claim 1, including a plurality of rows of the compartments defined by rows and columns of posts integrally moulded with the tray.

3. A microtitration plate as claimed in claim 2, wherein the posts are situated in a recess in the tray.

4. A microtitration plate as claimed in claim 3, wherein the outermost posts are half-posts moulded integrally with the side walls of the tray recess, and the inner posts are of lesser height than the outermost posts and the adjacent upper surface of the tray.

5. A microtitration plate as claimed in any one of the preceding claims, wherein the bottoms of the compartments have apertures extending through the tray bottom.

6. A microtitration plate as claimed in any one of the preceding claims, wherein the wells have flat optical quality bases, conical bases or part-spherical bases.

7. A microtitration plate as claimed in any one of the preceding claims, wherein the tops of the wells project above the upper surface of the tray.

8. A microtitration plate as claimed in any one of the preceding claims, wherein the tray is moulded from foam plastics material or silicone rubber.

9. A microtitration plate as claimed in any one of the preceding claims, wherein the tray has a peripheral rebate and a lid fits into the rebate and clears the tops of the wells.

10. A microtitration plate as claimed in any one of the preceding claims, wherein the wells are sealed by an adhesive cover strip.

11. A microtitration plate as claimed in any one of the preceding claims 1 to 9, wherein the wells are sealed by plugs carried by a cover strip.

12. A microtitration plate as claimed in claim 8 or 9, wherein the cover strip is perforated about the individual wells to facilitate selective opening of the wells.

13. A microtitration plate substantially as hereinbefore described with reference to Figures 1 to 5, and 7 to 10 of the accompanying drawings.

14. A microtitration plate substantially as hereinbefore described with reference to Figures 6 and 11 of the accompanying drawings.

15. A microtitration plate substantially as hereinbefore described with reference to Figure 14 of the accompanying drawings.

16. A microtitration plate substantially as hereinbefore described with reference to Figure 15 of the accompanying drawings.

17. A microtitration plate as claimed in claim 14, 15 or 15 and modified substantially as hereinbefore described with reference to either Figure 12 or Figure 13 of the accompanying drawings.