Fig. 3.

Enzymatic and clotting activities of Russell's viper venom. The metalloprotease ( A ), serine protease ( B ), and PLA ₂ ( C ) activities of various concentrations of Russell's viper venom were measured using respective fluorogenic substrates by spectrofluorimetry. The base level fluorescence obtained with negative controls (NC; i.e., the substrate in the absence of venom) at 90 minutes was taken as 100% to calculate the enzyme activities in venom samples at the same time point. The venom of Crotalus atrox (50 μg/mL) was used as a positive control (PC) in all these assays. 50 μg/mL Russell's viper venom was mixed with plasma and relevant reagents to measure PT ( D ) and aPTT ( E ) using Ceveron T100 fully automated coagulation analyzer. Data represent mean ± S.D. ( n  = 4). The p -values (* p  < 0.05, ** p  < 0.01 and **** p  < 0.0001) shown were calculated by one-way ANOVA ( A – C ) or unpaired t -test ( D and E ) using GraphPad Prism.