Nystatin is a polyene antifungal antibiotic produced by Streptomyces noursei. Nystatin acts by binding to ergosterols in fungal cell membranes, increasing permeability of the membrane, and creating nystatin/ergosterol based ion channels. It also functions as a lipid raft-inhibiting reagent and as membrane associated cholesterol. MW: 926.1. Purity Potency: ≥4400 U/mg