Isolation of nucleic acid

Abstract

The present invention provides a method of isolating nucleic acid from a sample, said method comprising contacting said sample with a detergent and a solid support, whereby soluble nucleic acid in said sample is bound to the support, and separating said support with bound nucleic acid from the sample. Where the method of the invention is used to isolate DNA, it may conveniently be couple with a further step to isolate RNA from the same sample.

1 . A method of isolating genomic DNA from a sample comprising cells, wherein the genomic DNA is present in the cells, the method comprising (a) contacting the sample with a solid support comprising an organic polymer, wherein the solid support selectively binds the cells, (b) contacting the cells bound to the solid support with a detergent in the absence of any chaotropic agent, whereby soluble genomic DNA becomes bound to the support in a sequence-independent manner in the presence of the detergent and absence of any chaotropic agent, and (c) separating the support with bound genomic DNA from the sample.  
   
   
       2 . The method of  claim 1 , wherein the solid support comprises an antibody or binding protein specific for the cells.  
   
   
       3 . The method of  claim 1 , wherein the solid support comprises an antibody specific for CD2 positive cells.  
   
   
       4 . The method of  claim 1 , wherein the detergent is anionic.  
   
   
       5 . The method of  claim 1 , wherein the detergent is sodium dodecyl sulphate, or another alkali metal alkylsulphate salt, or sarkosyl.  
   
   
       6 . The method of  claim 1 , wherein the concentration of detergent is 0.2% to 30% (w/v).  
   
   
       7 . The method of  claim 1 , wherein the detergent is contained in a composition additionally comprising one or more monovalent cations, chelating agents or reducing agents.  
   
   
       8 . The method of  claim 1 , wherein the detergent is used in alkaline solution.  
   
   
       9 . The method of  claim 1 , wherein the solid support is particulate.  
   
   
       10 . The method of  claim 1 , wherein the solid support comprises magnetic beads.  
   
   
       11 . The method of  claim 1 , wherein the solid support has a hydrophobic surface.  
   
   
       12 . The method of  claim 1 , wherein the genomic DNA is eluted from the support, following separation from the sample.  
   
   
       13 . The method of  claim 12 , wherein the genomic DNA is eluted by heating.  
   
   
       14 . The method of  claim 1 , wherein the organic polymer is polyurethane.  
   
   
       15 . The method of  claim 1 , wherein the organic polymer is polystyrene.  
   
   
       16 . The method of  claim 1 , wherein the organic polymer is latex.  
   
   
       17 . The method of  claim 1 , wherein the solid support comprises superparamagnetic polystyrene beads.  
   
   
       18 . The method of  claim 1 , wherein the solid support is porous.  
   
   
       19 . The method of  claim 1 , further comprising the step of detecting, hybridizing, amplifying or quantifying the bound genomic DNA after the separating step.  
   
   
       20 . A method of isolating RNA and genomic DNA from a sample comprising cells, wherein the RNA and genomic DNA are present inside the cells, the method comprising (a) contacting the sample with a solid support comprising an organic polymer, wherein the solid support selectively binds the cells, (b) contacting the cells bound to the support with a detergent in the absence of any chaotropic agent, whereby soluble genomic DNA in the sample is bound to the support in a sequence-independent manner in the presence of the detergent and absence of any chaotropic agent; (c) separating the support with bound genomic DNA from the sample; and (d) isolating RNA from the sample.