citrated blood

For in vitro aggregation studies citrated blood is carefully centrifuged to produce platelet-rich plasma.

Coagulation requires citrated blood samples to analyze blood clotting times and coagulation factors.

Each of the three women rubbed a drop of something (it was actually Seaton's citrated blood) between thumb and forefinger and Madame Barlo said:

They found it was related antigenically to the prothrombin activator of O. scutellatus venom, able to activate citrated blood plasma, wartrin plasma, factor V and factor X deficient plasmas and will hydrolyse peptide p-nitroanilide substrate S-2222.