SDS-polyacrylamide gel electrophoretic determination of type I and type III collagen in small skin samples.

A sodium dodecylsulfate-polyacrylamide electrophoretic method, which in contrast to other biochemical procedures, e.g. differential salt precipitation or ion exchange chromatography and molecular sieve chromatography, is applicable to smallest amounts of protein, is shown to be suitable for the determination of the collagen types from small skin samples, such as routine skin biopsies. After urea extraction, the tissue samples are cleaved with cyanogen bromide. The resulting CNBr peptides derived from the different alpha-chains are resolved in 12% SDS-polyacrylamide gels. Densitometric profiles of the gel electrophoretic patterns correspond to the collagen type content of the tissue specimens. Comparing fetal to adult skin, the higher content of type III collagen in the case of fetal skin can be demonstrated.