Apparatus and method for conducting assays

Abstract

A multi-well assay plate structure ( 54 ) and assay apparatus and a method for performing chemical biochemical assays is described. The multi-well assay plate structure ( 54 ) defines a relatively shallow substantially enclosed space ( 71 ) above a plurality of wells ( 76 ), with the enclosed space ( 71 ) having an inlet ( 72 ) and an outlet ( 22 ) separate from the inlet. Fluid introduced via the inlet ( 72 ) flows into the space ( 71 ) and/or wells ( 76 ) by displacing air. Withdrawal of the fluid via the inlet ( 72 ) or outlet leaves fluid in the wells ( 76 ) allowing various tests to be performed. Various embodiments of the structure are described. The preferred arrangement embodies the structure on a transparent plastic disk which can be used with automatic fluid handling apparatus ( 80 ) and the results assessed using optical assessment apparatus ( 81 ). The apparatus can be used to perform a variety of assays but, in particular, biochemical/chemical assay, immunoassays and genetic (DNA) assays and it can be used in a laboratory for multiple sample testing or at a point-of-care, i.e. in a surgery or clinic.

1 . An assay plate structure for use in conducting optical assays of a fluid analyte, the plate structure comprising:
 a disc for rotation about a central axis, the disc having upper and lower plates. spaced apart a distance to facilitate the flow of a fluid between said plates by capillary action and a plurality of substantially radially extending walls disposed between the plates, said walls subdividing the disc into a plurality of disc sectors; and   a plurality of disc inserts arranged to be received by respective disc sectors and to be retained therein,   the structure further including a plurality of openings through the upper plate, at least one opening above each disc sector for introducing a liquid analyte into the sector space between the upper plate and the disc insert, the upper surface of each disc insert and the opposed surface of the upper plate being substantially planar, and the flow of fluid between the upper plate and the disc insert being facilitated by capillary action.   
     
     
         2 . The assay plate structure of  claim 1  wherein a vent opening is provided for each disc segment around the periphery thereof, between the radially outer edge of the upper plate and each disc insert. 
     
     
         3 . The assay plate structure of  claim 1  wherein the plate structure is provided in the form of a disc and includes digitally encoded address information. 
     
     
         4 . The assay plate structure of  claim 1  wherein the plate structure is transparent for an optical inspection of said wells from outside structure. 
     
     
         5 . A chemical/biochemical assay apparatus comprising an assay plate structure in accordance with  claim 1  and having a plurality of wells for receiving samples to be. assayed, said assay apparatus further including:
 fluid handling means for introducing and removing fluid reagents into said assay plate structure to allow a fluid reagent mixture to be retained in each well, and   optical assessment means for measuring optical result of the reaction in each well.   
     
     
         6 . An assay structure for use in conducting optical assays of a fluid analyte, the structure comprising,
 a disc for rotation about a central axis, the disc including optically readable digitally encoded address information provided therein for optical inspection thereof from externally of said disc and said disc have one or more disc insert receiving sectors;   one or more disc inserts to be received by a respective disc sectors and to be retained therein,   the structure further including one or more openings within the disc to provide, at least one opening relative a disc sector for fluid communication with a disc insert received in said sector.   
     
     
         7 . The assay structure of  claim 6  wherein a vent opening is provided in said disc for a disc sector. 
     
     
         8 . The assay structure of  claim 6  wherein the one or more disc inserts are snap-fitted to the disc. 
     
     
         9 . The assay structure of  claim 6  wherein the disc inserts and the disc include lock and key portions to allow the inserts to be snap-fitted to the disc in a correct orientation only. 
     
     
         10 . The assay structure of  claim 6  wherein the disc and inserts are made of optically transmissive plastic.