Periodic Acid-Schiff Staining of Retinal Whole Mounts

Abstract

Introduction Study of the vasculature in rat retina has been largely dependent upon methods which involve intravascular injection or serial tissue sections. The method that Friedenwald and Becker developed (Friedenwald, 1949), whereby human retinae were stained with a periodic acid-Schiff reaction and examined as flat mounts, revealed the vascular tree by staining its endothelial basement membrane. The method has appeared to offer a convenient and new approach to studies of retinopathy in the rat. However, the method has been reported to overstain rat retina (Keeney and Barlow, 1955, 1956), and a similar difficulty has been encountered with other mammalian retinae unless autolyzed prior to fixation. Kuwabara and Cogan (1960) have digested retinae of rats and other mammals with trypsin and have removed the extravascular tissue, the resulting networks of vessels later being stained with hematoxylin and eosin in addition to a periodic acid-Schiff reaction. Keeney and Barlow (1956) reported that