Abstract

The difficulty of using a single method for staining rat and human pituitary was investigated by testing separately and in different combinations the effects of the various components in the performic-acid-alcian-blue(P.F.A.B.)-periodic-acid-Schiff(P.A.S.) method (Adams and Swettenham, 1958). In this way the possibility of inhibiting or enhancing by one procedure the staining effects of the other could be assessed. The profound influence of fixation on these staining methods was demonstrated by employing the same set of staining methods on tissues fixed in different ways.

The possibility that unbuffered performic acid might exert a considerable solvent action on certain proteins was considered to be related to the difficulty of applying the P.F.A.B.-P.A.S. method to the rat pituitary. Buffered performic acid has far less solvent action and the P.F.A.B.-P.A.S. method, modified by the replacement of buffered for unbuffered performic acid, proved to be successful in the demonstration of two types of basophil cells in both rat and man.