Method for intensifying the optical detection of samples that are held in solution in the through-hole wells of a holding tray

Abstract

A system and method for optically detecting samples held in a solution requires the use of a holding plate that has as many as one-thousand through-hole wells, or more. The solution is suspended in these through-hole wells under surface tension between opposed surfaces of the holding plate. A pneumatic pump is then engaged with the plate to establish a differential pressure (Δp) between the upper and lower surfaces of the solution that is equal to approximately two tenths of a pound per square inch (0.2 psi). The result is the formation of a convex meniscus on a surface of the solution that causes light passing into the solution to converge and concentrate. This concentration of light, in turn, facilitates optical detection of samples in the solution.

What is claimed is:  
     
         1 . A system for optically detecting samples held in a solution which comprises: 
 a holding plate having a first surface and a second surface with a plurality of through-hole wells therethrough; and    a pneumatic means engageable with said plate for creating a differential pressure (Δp) between said first and second surfaces of said holding plate to force said solution in said through-hole wells toward said first surface of said plate to uniformly position solution in each said through-hole well at said first surface to facilitate optical detection of said samples in said solution.    
     
     
         2 . A system as recited in  claim 1  wherein said pneumatic means is an air pump.  
     
     
         3 . A system as recited in  claim 2  wherein said differential pressure (Δp) is approximately two tenths of a pound per square inch (0.2 psi).  
     
     
         4 . A system as recited in  claim 1  further comprising an optical means for directing light through the convex meniscus.  
     
     
         5 . A system as recited in  claim 1  further comprising a hydrophobic coating on said first surface to enhance uniformity in the positions of solutions at said first surface.  
     
     
         6 . A system as recited in  claim 1  wherein each of said through-hole wells in said holding plate has an aspect ratio greater than 5:1 and an inner diameter less than approximately five hundred microns.  
     
     
         7 . A system as recited in  claim 1  wherein solution in each said through-hole well has a substantially convex meniscus.  
     
     
         8 . A system as recited in  claim 1  wherein solution in each said through-hole well has a substantially concave meniscus.  
     
     
         9 . A system for optically detecting samples held in a solution which comprises: 
 a holding plate having a first surface and a second surface with a plurality of through-hole wells extending therebetween, for suspending said solution therein under surface tension between said first and second surfaces of said holding plate, said suspended solution having an upper surface exposed to ambient conditions and a lower surface exposed to said same ambient conditions; and    a pneumatic means engageable with said mechanical means for moving said upper surface of said solution in each said through-hole well to said first surface of said holding plate to uniformly position said upper surface of said solution at said first surface of said holding plate to facilitate optical detection of said samples in said solution.    
     
     
         10 . A system as recited in  claim 9  wherein each of said through-hole wells in said holding plate has an aspect ratio greater than 5:1 and an inner diameter less than approximately five hundred microns.  
     
     
         11 . A system as recited in  claim 9  wherein said pneumatic means is an air pump for creating a differential pressure (Δp) between said upper and lower surfaces of said solution.  
     
     
         12 . A system as recited in  claim 11  wherein said differential pressure (Δp) is approximately two tenths of a pound per square inch (0.2 psi).  
     
     
         13 . A system as recited in  claim 9  further comprising an optical means for directing light through solution in each said through-hole well.  
     
     
         14 . A system as recited in  claim 9  further comprising a hydrophobic coating on said first surface to enhance uniformity in the positions of solutions at said first surface.  
     
     
         15 . A system as recited in  claim 9  wherein solution in each said through-hole well has a substantially convex meniscus.  
     
     
         16 . A system as recited in  claim 9  wherein solution in each said through-hole well has a substantially concave meniscus.  
     
     
         17 . A method for optically detecting samples held in a solution which comprises the steps of: 
 providing a holding plate having a first surface and a second surface with a plurality of through-hole wells therethrough for suspending said solution under surface tension in respective said through-hole wells between said first and second surfaces of said holding plate, said suspended solution having an upper surface exposed to ambient conditions and a lower surface exposed to said same ambient conditions;    engaging a pneumatic means with said plate to uniformly position said upper surface of said solution in each said through-hole well at said first surface of said holding plate; and    directing light through said solution to cause light passing therethrough to converge and concentrate in said solution to facilitate optical detection of said samples in said solution.    
     
     
         18 . A method as recited in  claim 17  wherein each of said through-hole wells in said holding plate has an aspect ratio greater than 5:1 and an inner diameter less than approximately five hundred microns, and wherein said holding plate has more than one thousand said through-hole wells, and further wherein said pneumatic means is an air pump for creating a differential pressure (Δp) between said upper and lower surfaces of said solution with said differential pressure (Δp) being approximately two tenths of a pound per square inch (0.2 psi).  
     
     
         19 . A method as recited in  claim 17  wherein solution in each said through-hole well has a substantially convex meniscus.  
     
     
         20 . A method as recited in  claim 17  wherein solution in each said through-hole well has a substantially concave meniscus.