Sensitive silver staining of proteins after isoelectric focusing in agarose gels

Abstract As isoelectric focusing in agarose gels has many merits it is valuable to be able to visualize proteins at concentrations lower than detectable with Coomassie Brilliant Blue R‐250 staining. A silver staining procedure has been adapted to such gels and many proteins including serum samples have been studied. Silver staining gave very sharp protein bands and was about 30 times more sensitive than Coomassie Brilliant Blue R‐250 staining. This is important to allow direct application of dilute protein solutions such as urine and cerebrospinal fluid. This may also avoid artifacts e.g. caused by concentration methods.