Stypven
Time - 1
Specimen requirements:
Fresh whole blood collected in
sodium citrate at a 9:1 ratio of blood to anticoagulant
Principle:
Ca++ is bound by sodium citrate keeping blood from
clotting
Specimen centrifuged and plasma used
in testing
Plasma is mixed with reagent
containing:
Ca++
Tested within 2 hours (4 hours if
refrig) or stored at -20oC for 2 – 5 days
Russell’s viper venom (stypven)
Phospholipid substitute
for PF3
Timer started with addition of
reagents and stopped when clot detected