Estimation of types I and III collagens in whole tissue by quantitation of CNBr peptides on SDS-polyacrylamide gels.

The electrophoretic and staining characteristics of CNBr peptides of purified bovine and human types I and III collagens were investigated on SDS-polyacrylamide slab gels. All the major CNBr peptides of both types of collagen showed linear staining characteristics with Coomassie brilliant blue up to a total protein concentration of 150 micrograms per gel track. The amount of each type of collagen present in model mixtures was calculated from quantitations of the alpha 1(I)CB8 (type I) and alpha 1(III)CB8 (type III) peptides after resolution on 10% (w/v) SDS-polyacrylamide slab gels. The accuracy of the method was assessed, shown to give less than 15% error in mixtures containing more than 15% type III, and its applicability to the estimation of ratios of type I and type III collagens in whole tissue was determined.