A high-spatial-resolution laser beam densitometer for quantitative analysis of polyacrylamide gels.

Quantitative analysis of proteins separated on polyacrylamide gels requires the use of an accurate, sensitive scanning device. An easily constructed, high-resolution laser beam densitometer is described in this report. The apparatus was built from readily obtainable but precision optical, electronic, and mechanical components. It was designed for and successfully applied to analysis of microslab gels, but also can be used for scanning of cylindrical gels, autoradiographs, and, with simple modification, larger slab gels.