生物素-VAD-FMK是一种细胞可渗透的生物素标记的泛半胱天冬酶抑制剂，用于鉴定细胞裂解物中的活性胱天蛋白酶。生物素-VAD-FMK是不可逆的半胱天冬酶抑制剂，与多种活性胱天蛋白酶的活性腔共价结合。在生物素-VAD-fmk对活性胱天蛋白酶的亲和标记是在TNFα/ ActD处理过的细胞的裂解物中超过95％的caspase-3样活性失活的条件下进行的。生物素-VAD-FMK是不可逆的泛酶抑制剂。在体外抑制TNFα介导的细胞凋亡（IC50 = 0.7μM）。 Biotin-VAD-FMK is a cell permeable biotin-labeled pan-caspase inhibitor used to identify active caspases in cell lysates. Biotin-VAD-FMK is an irreversible caspase inhibitor that covalently binds to the active cavity of a wide spectrum of active caspases. Affinity labeling of active caspases with biotin-VAD-fmk was carried out under conditions where more than 95% of caspase-3-like activity was inactivated in lysates from TNFα/ActD-treated cells. Biotin-VAD-FMK is an irreversible, pancaspase inhibitor. Inhibits TNFα-mediated apoptosis in vitro (IC50 = 0.7 μM).