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 double-stain, 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 dark-violet, 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.