Method and Apparatus for Performing Microassays

Abstract

A method and apparatus for analyzing a plurality of substances. A platen is provided having two substantially parallel planar surfaces and a plurality of through-holes. An optical arrangement analyzes light emanating from the through-holes. The through-holes may be individually addressable, and may have volumes less than 100 nanoliters. Samples may be accurately dispensed, diluted and mixed in accordance with embodiments of the invention, and may be plated onto walls of the through-holes, and then subsequently resuspended prior to characterization, or, alternatively, retained in the through-holes by surface tension.

I claim: 
     
         1 . A method for analyzing specified properties of a set of substances, the method comprising:
 a. providing a platen having two substantially parallel planar surfaces, an inner layer of hydrophilic material and two outer layers of hydrophobic material coupled to opposite sides of the inner layer, and a two-dimensional array of addressable through-holes having an areal density of at least 1.6 through-holes per square millimeter,   b. retaining a set of distinct substances in respective through-holes of the array in such a manner that a first through-hole contains a first substance distinct from a second substance contained in an adjacent through-hole to the first through-hole;   c. adding a liquid into at least one of the through-holes containing a substance for permitting a reaction between the liquid and the substance; and   d. characterizing contents of distinct through-holes in terms of the specified properties.   
     
     
         2 . A method according to  claim 1 , wherein the set of different substances includes a reagent. 
     
     
         3 . A method according to  claim 1 , wherein the set of different substances comprises a library of at least 1000 substances. 
     
     
         4 . A method according to  claim 1 , wherein the set of different substances include optical taggants. 
     
     
         5 . A method according to  claim 1 , wherein the step of retaining the set of distinct substances further includes: loading the set of distinct substances in one of liquid solution and suspension; and forming coatings of the distinct substances so as to retain the distinct substances on walls of the through-holes. 
     
     
         6 . A method according to  claim 1 , wherein the step of adding a liquid includes adding a liquid substantially uniformly to the through-holes of the array. 
     
     
         7 . A method according to  claim 6 , wherein the step of adding a liquid includes resuspending the distinct substances in liquid by means of wetting. 
     
     
         8 . A method according to  claim 1 , wherein the step of characterizing contents of distinct through-holes includes characterizing by optical methods. 
     
     
         9 . A method according to  claim 8 , wherein the step of characterizing contents of distinct through-holes includes characterizing by fluorometric methods. 
     
     
         10 . A platen for retaining biological samples, the platen comprising:
 a. an inner layer of hydrophilic material and two outer layers of hydrophobic material coupled to opposite sides of the inner layer;   b. a two-dimensional array of addressable through-holes having an areal density of at least 1.6 through-holes per square millimeter,   c. a set of distinct substances in respective through-holes of the array.   
     
     
         11 . A platen according to  claim 10 , wherein distinct substances of the set of distinct substances are coated on walls of the through-holes. 
     
     
         12 . A platen according to  claim 10 , wherein distinct substances of the set of distinct substances are retained within through-holes of the platen by surface tension.