Abstract
1. The concentration of Bromophenol Blue used as tracking dye in polyacrylamide-gel electrophoresis affected the resolution of rat neurophysins. 2. A final dye concentration of 1mug/ml in the tris-glycine running buffer was found to give the best results. 3. The presence of two major and one minor neurophysin(s) in the rat was confirmed. 4. The two major proteins were found to re-run as single discrete bands, which had the same mobilities in the absence of dye and different mobilities in its presence.