(-)-Blebbistatin, 5 mg

Supplied by STEMCELL Technologies, this selective cell-permeable inhibitor targets non-muscle myosin II (NM II) ATPases and is named for its ability to block membrane blebbing. It rapidly and reversibly inhibits Mg-ATPase activity and the in vitro motility of non-muscle myosin IIA and IIB across several species, with reported IC₅₀ values of 0.5 - 5.0 µM, while only poorly inhibiting smooth muscle myosin (IC₅₀ = 80 µM). The compound is inactivated by UV light, which is particularly relevant for fluorescent cell imaging. It is provided as a crystalline solid of ≥ 98% purity (CAS 856925-71-8; chemical formula C₁₈H₁₆N₂O₂; molecular weight 292.3 g/mol), is stable at -20°C when protected from prolonged light exposure, and is soluble in DMSO at concentrations ≤ 40 mM, though it has low solubility in aqueous media.

Published applications include increasing human pluripotent stem cell (hPSC) survival and cloning efficiency after single-cell dissociation (downstream of ROCK inhibition), enabling hPSC culture on microcarriers without surface coating, and inhibiting differentiation of human mesenchymal stem cells. The product is categorized within the RHO/ROCK pathway research workflow as a non-muscle myosin II ATPase inhibitor.