Electrophoretic in situ tissue staining

Abstract

The present invention introduces a radically different way of accelerating biomolecule conjugates into tissue, and hence towards their targets for purposes of tissue staining. The invention provides for an order of magnitude improvement over the prior art diffusion process used to stain tissue. The invention comprises a method of tissue staining by applying an electric field to a tissue sample in the presence of an electrolyte and biomolecular conjugates of interest suspended in the electrolyte. Typical staining times are reduced to seconds as opposed to 30-120 minutes common in the prior art. The invention is also directed to devices for performing the method.

1 . A method of introducing a conjugate molecule into tissue comprising applying an electric field to the tissue in the presence of an electrolyte and a conjugate molecule of interest suspended in the electrolyte.  
     
     
         2 . The method of  claim 1  wherein said conjugate molecule is any molecule that has a complementary binding portion.  
     
     
         3 . The method of  claim 1  wherein said conjugate molecule is selected from the group consisting of antibodies and polynucleotide molecules.  
     
     
         4 . The method of  claim 1  wherein said tissue comprises a solid tissue sample.  
     
     
         5 . The method of  claim 1  wherein said tissue comprises a cellular preparation.  
     
     
         6 . The method of  claim 1  wherein the step of applying the electric field to the tissue comprises using alternating current.  
     
     
         7 . The method of  claim 1  wherein the step of applying the electric field to the tissue comprises using direct current.  
     
     
         8 . The method of  claim 1  wherein the step of applying the electric field to the tissue comprises orienting the electric field orthogonally to the plane of the tissue.  
     
     
         9 . The method of  claim 3  wherein said conjugate molecule is detectably labeled.  
     
     
         10 . The method of  claim 9  wherein the labels are selected from the group consisting of haptens, fluorophores, radiolabels and chromophores.  
     
     
         11 . A device for electrophoretically directing conjugate molecules into a tissue sample comprising: 
 (a) a first electrode having a sample surface adapted for positioning and holding said tissue;    (b) a second electrode spaced apart from said first electrode and defining a gap between said sample surface and said second electrode;    (c) a resevoir suitable for holding an electrolyte solution disposed on both sides of the tissue sample; and    (d) means for applying an electrical current across said sample surface whereby in response to it an electric field will form sufficient to drive the conjugate molecules into said tissue.    
     
     
         12 . A device for electrophoretically directing conjugate molecules into a tissue sample comprising: 
 (a) a first electrode having a sample surface adapted for positioning and holding said tissue;    (b) a second electrode spaced apart from said first electrode and defining a gap between said sample surface and said second electrode, said gap capable of supporting a meniscus of electrolye fluid; and    (c) means for applying an electrical current across said sample surface whereby in response to it an electric field will form sufficient to drive the conjugate molecules into said tissue.    
     
     
         13 . A device for electrophoretically directing conjugate molecules into a tissue sample comprising: 
 (a) a movable electrically-insulated block, said block having at least two electrodes of opposite polarity positioned on it, said block being movable to thereby direct an electric field into said tissue sample;    (b) a sample surface adapted for positioning and holding said tissue, said sample surface being spaced apart from said block thereby defining a gap between said sample surface and said block, said gap capable of supporting a meniscus of electrolye fluid; and    (c) means for applying an electrical current across said electrodes whereby in response to it an electric field will form sufficient to drive the conjugate molecules into said tissue.