Gel for Isoelectric Focusing

Abstract

The present invention relates to the field of electrophoresis and more specifically to a gel or strip for separating peptide components by isoelectric focusing by producing IPG (immobilised pH gradient) gels or strips in a novel way before focusing. More closely, the peptides are focused in a novel IPG gel including an uneven or non-linear pH gradient having at least three separate stepwise arranged pH-intervals. After focusing the peptide resolution is high and the peptides are evenly distributed along the gel.

1 . A gel for isoelectric focusing of peptides comprising a non-linear immobilised pH gradient including at least three separate stepwise arranged pH-intervals, wherein the peptides are evenly distributed along the gel after isoelectric focusing. 
   
   
       2 . The gel of  claim 1 , wherein said gel is adopted to peptides obtained by tryptic digestion of peptides. 
   
   
       3 . The gel of  claim 1 , wherein the gel is pre-cast. 
   
   
       4 . The gel of  claim 1  wherein the gel is dried. 
   
   
       5 . The gel of  claim 4 , wherein the gel is rehydrated to less than its original wet thickness. 
   
   
       6 . The gel of  claim 5 , wherein the gel is rehydrated to 40-90% of its original wet thickness. 
   
   
       7 . The gel of  claim 6 , wherein the gel is rehydrated to 60% of its original wet thickness. 
   
   
       8 . The gel of  claim 1 , wherein the gel comprises three separate gel pieces each representing the separate pH-intervals, wherein the three pieces are joined together to form a continuous gel. 
   
   
       9 . A kit comprising the gel of  claim 4  and a sample application bridge comprising denaturant buffer. 
   
   
       10 . The kit of  claim 9 , wherein the gel comprises urea and sample application bridge is saturated with 8M urea. 
   
   
       11 . The kit of  claim 9 , wherein the sample application bridge is made of paper or hydrogel.