Determination of myosin light chain phosphorylation using astronomical image analysis programs on autoradiographs of electrophoretic gels.

Computer image analysis programs developed by astronomers for celestial photometry were used for the analysis of autoradiographs of electrophoretic slab gels. Oxytocin-stimulated myosin light chain phosphorylation in mammary myoepithelial cells was studied by incubating cells with [32P]orthophosphate followed by oxytocin addition, polyacrylamide gel electrophoresis of cellular protein, and autoradiography of electrophoretic slab gels. After scanning and digitization of autoradiographs, [32P]phosphate incorporation into the myosin light chain was measured by the determination of radiation flux recorded on the X-ray film. Within seconds after oxytocin addition, the myosin light chain was fully phosphorylated. The large library of astronomical computer programs has applications for the quantitative analysis of both one- and two-dimensional electrophoretic gels.