When one plus one equals more than two - A novel stain for renal biopsies is a combination of two classical stains

Histologic evaluation of renal biopsies includes multiple ancillary stains, including Periodic acid-Schiff's (PAS) and Masson's trichrome (Trichrome). Herein we report an innovative doublestain, derived from two standard stains (PAS and Trichrome). This novel stain not only has advantages of both ancestor stains, but became more distinguishable and colorful, when basement membranes stain darkviolet, whereas the interstitial collagen remains blue. This allows the pathologist immediate estimation of the amount of collagen, tubular atrophy and the degree of interstitial fibrosis in one section. Using computer-based analysis, we confirmed that our innovative double-stain highlights interstitial collagen better than Trichrome stain alone. We strongly recommend renal pathologists to try this innovative stain in their practice.