Periodic Acid Schiff or PAS Staining: A Method to Assess the Structural Deformities of Glomerulus

For detailed visualization of the glomerular cells and mesangial matrix, dry the fixed paraffin-embedded kidney cortex samples at 37 degrees Celsius for 1 hour, followed by deparaffinization with consecutive xylene and descending ethanol immersions. Rehydrate the samples in distilled water for 5 minutes and incubate the slides in Periodic Acid solution in a fume cabinet.

After 5 minutes, rinse the slides with three 5-minute washes in 100 milliliters of distilled water, followed by a 15-minute incubation in Schiff's reagent. At the end of the incubation, wash the slides in running tap water for 5 minutes and counterstain with hematoxylin for 3 seconds before thoroughly rinsing in running tap water for another 15 minutes.

Then, dehydrate the slides with ascending ethanol immersions and two consecutive 3-minute xylene immersions. After air drying, the slides can be mounted with xylene based mounting medium for assessment of their glomerular structure on a light microscope at a 400X magnification.