Patent ID: 6972326

Claim:
A method of labeling poly(amino acids) comprising the steps of: a. separating poly(amino acids) by gel electrophoresis, resulting in separated poly (amino acids); b. transferring said separated poly(amino acids) to a solid support, resulting in immobilized poly(amino acids); c. combining said immobilized poly(amino acids) on said solid support with a labeling mixture that comprises one or more chemically reactive dipyrrometheneboron difluoride dyes of the formula: wherein each of R 1 through R 7 are independently selected from the group consisting of H, halogen, —L—Rx, substituted or unsubstituted C 1 –C 6 alkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylethenyl, substituted or unsubstituted arylbutadienyl, and substituted or unsubstituted heteroaryl wherein at least one of R 1 through R 7 is —L—Rx, wherein L is a spacer having 1–24 nonhydrogen atoms and Rx is a maleimide or a succinimidyl ester of a carboxylic acid; d. incubating the immobilized poly(amino acids) in the labeling mixture for a sufficient time for the chemically reactive dipyrrometheneboron difluoride dyes to form a covalent bond with said poly(amino acids), resulting in labeled poly(amino acids).