Fast and Efficient Method for Detection and Estimation of Proteins

A quick, simple, inexpensive and sensitive method is described to stain and quantitate proteins on nitrocellulose papers. The proteins may be spotted or transferred from polyacrylamide gels by Western blotting. The procedure involves non-radioactive iodination of the polypeptides by chloramine T and potassium iodide followed by detection of bound iodine with starch. The method is more sensitive and much quicker than Coomassie brilliant blue staining and may be used for quantitation or detection of proteins in unknown samples. Another major advantage of this procedure is that ionic or nonionic detergents, although at higher concentrations causing the sample to disperse more broadly in the membranes, do not affect the staining procedure. Further, this method may be used for detection of proteins bound to papers that have high affinity for proteins such as the Zeta probe membranes.