Thiosemicarbazide used after periodic acid makes methenamine silver staining of renal glomerular basement membranes faster and cleaner.

The periodic acid-methenamine silver staining technique, which is frequently used for demonstrating the renal glomerular basement membrane, requires a high degree of skill, and in some cases it may be difficult to obtain a good result. To overcome such difficulty and inconsistency, we have improved the method by performing methenamine silver staining after oxidation with periodic acid and subsequent application of thiosemicarbazide. In this procedure, this semicarbazide enhanced the reaction of methenamine silver with the glomerular basement membrane and the reaction was completed within a shorter time in comparison with the conventional method. This modification also eliminated any nonspecific reaction with the surface of the glass slide and the solution container and yielded excellent and reproducible results irrespective of the fixation method and material employed. It was also found to stain the renal glomerular basement membrane of rabbits, which is demonstrable only with difficulty by the conventional method.