Consecutive radiofluorography and silver staining of two‐dimensional gel electrophoretograms: Application in determining the biosynthesis of serum and tissue proteins

The methodology for conventional radiofluorography of two‐dimensional gels, followed by rehydration of the gel and subsequent silver staining, is described. The image obtained by radiofluorography is referred to as biosynthetic image, and the image obtained by silver staining as constitutive image. Since the two images are already in close register (the same gel), reliable identification of polypeptides by the two different assays is possible, and the comparison provides valuable information on the catabolism of each entity. The utility of this procedure is illustrated in experiments involving a labeling with L‐[³⁵S] methionine of an entire mouse. Both serum and tissue samples were analyzed by two‐dimensional gel electrophoresis with the aim of determining several categories of polypeptides in terms of their biosynthetic rates and their composition.