活力定義:One unit will activate that amount of plasminogen which will produce a ΔA275 of 1.0 per ml per minute at pH 7.5 at 37 °C, when measuring perchloric acid soluble products from α-casein (1 cm light path).

穩(wěn)定性：干粉在4℃較穩(wěn)定，水溶液在4℃的穩(wěn)定期為3天。