Two new staining procedures for quantitative estimation of proteins on electrophoretic strips.

Two new procedures are described for the estimation of protein by direct photometry on electrophoretic strips. The protein complexes of procion brilliant blue RS and coomassie brilliant blue R250 are shown to follow Beer's law up to 50 and 20 microg/cm, respectively. The lower limits of detection are 2 and 0.5 microg/cm. Within these ranges the absolute amount of protein can be estimated within a single test with an accuracy of about +/-10%. The major contribution to the error arises from uneven application of the samples. Relative concentrations within a mixture of proteins can be evaluated to an accuracy better than +/-3%. Technical details of the procedures and of the equipment required are given in full, and their areas of usefulness discussed.