Stypven time

Specimen:

4.5 mL blood added to 0.5 mL citrate.

Method:

Recalcification of platelet-poor plasma at 37°C in presence of Stypven (Russell viper venom) and phospholipid.

The clotting time is recorded.

Reference Interval:

Consult pathologist.

Application:

Investigation of possible bleeding disorder.

Interpretation:

Stypven activates factor X directly, thus the Stypven time is normal in factor VII deficiency, but abnormal in factor V, II and most cases of factor X deficiency.

Reference:

Bain et al. Dacie and Lewis Practical Haematology. 11th Ed. 2012.