A rapid and sensitive method for detection of proteins in polyacrylamide SDS gels: staining with ethidium bromide.

We describe here a fluorometric method of detection of proteins fractionated by electrophoresis in polyacrylamide-SDS gels. This method, using ethidium bromide as fluorescent dye, is performed within 40 minutes after the end of the electrophoretic run. It does not require treatment of proteins prior to electrophoresis, and entails neither fixation of proteins in the gel, nor destaining. It is sufficiently sensitive to detect 0.5 - 1.0 microgram of protein per band. Furthermore, the simultaneous electrophoretic resolution and detection of protein and RNA on a single SDS-polyacrylamide gradient gel is reported.