Streptokinase

Human venous blood was collected from healthy consenting volunteers using butterfly needles (BD Vacutainer, BD Safety-Lok, Cat # 367283BD, Franklin Lakes, NJ) and stored in 4.5 mL citrated tubes (BD Vacutainer, Buffered Cit. Na., Cat # 366415), and kept at 22 °C Blood sample procurement protocols were approved by IRB of the University of North Carolina at Chapel Hill (IRB # 12-1592). Blood samples were used within 24h of collection and run as split specimens on the ASAP system and a TEG 5000 analyzer (Heomentics, Inc). For the dilution experiments, isotonic saline (0.90% w/v NaCl) was added to the blood and mixed by gently inverting the tube. Streptokinase, purchased from Sigma-Aldrich (product # S3134-10KU), was diluted to a final concentration of 9.6 U/ml for the high dose lysis experiment (Figure 4, blue circles) and 1.2 U/mL for the low dose lysis experiment (Figure 4, green squares). Immediately prior to data collection, all specimens were re-calcified by adding 1 μL of 0.2M CaCl per 17 μL of specimen volume. A 20 μL droplet of blood was pipetted onto the opening of the micro-fluidic device, and the blood wicked into the channel. The final, as tested, specimen volumes for the ASAP and TEG systems were 20 μL and 360 μL, respectively. The TEG was run according to standard operating procedures.