Sharply Resolving Labeled Protein Molecular Weight Standards

Abstract

Pre-labeled protein standards useful in electrophoresis that have sharp, consistent separation characteristics that are substantially the same as those of their unlabeled counterparts are provided. The invention provides pre-labeled protein standard sets that include a plurality of labeled proteins that are labeled on a first amino acid, in which side reactions of the label with amino acids not targeted for labeling are reduced.

1 - 89 . (canceled) 
     
     
         90 . A method of characterizing one or more proteins comprising: (a) electrophoresing one or more proteins and at least one prelabeled protein standard set of claim  1  or claim  25  in a gel; and (b) comparing the migration of the one or more proteins with the migration of least one protein standard of the pre-labeled standard set. 
     
     
         91 . The method of  claim 90 , further comprising (c) determining the molecular weight of the one or more proteins. 
     
     
         92 . The method of  claim 90 , wherein at least two of the two or more protein standards having molecular weights of 10 kDa or greater migrate within 5% of the distance of the that the same protein standard in unlabeled form migrates. 
     
     
         93 . The method of  claim 90 , wherein the width of the bands on a gel of each of the electrophoresed protein standards of the set having a molecular weight of 10 kDa or greater does not vary by more than 2-fold. 
     
     
         94 . The method of  claim 93 , wherein the band intensities of the protein standards of the pre-labeled protein standard set having molecular weights of 10 kDa or greater does not vary by more than 2.5 fold.