QUANTITATION OF COLLAGEN IN POLYACRYLAMIDE GELS BY FLUORESCENT SCANNING OF MDPF-LABELED PROTEINS - IMPROVEMENT OVER DENSITOMETRIC SCANNING OF GELS STAINED BY COOMASSIE BLUE

Purified α chains of collagen were made fluorescent by coupling with 2-methoxy-2,4-diphenyl-3(2H)-furanone (MDPF) and then electrophoresed on sodium dodecyl sulfate-polyacrylamide gels. The migration of MDPF-labeled collagen was similar to unlabeled collagen α chains except that MDPF-α1(I) migrated closer to MDPF-α2. The area under the peaks recorded from fluorometric scanning of MDPF-labeled α1(I), α2, and α1(III) was linear from 10-5 to 10-8 g. The standard curves for the three α chains were similar. The results from nonreplicate determinations had ±6% SE. This method is an improvement over staining with Coomassie blue. It has a greater sensitivity, peak area is independent of migration distance, has a wider range of linearity, and permits observation of bands during electrophoresis with quantitation immediately after electrophoresis. © 1978.