Rapid fluorometric assay for plasma warfarin.

As in all fluorometric procedures, glassware, reagents, and specimens must be kept free of fluorescent contamination. Glassware must be cleaned with an inorganic detergent and rinsed with distilled water. Paraflim should be used to seal tubes for mixing procedures. Ten milliliters of venous blood was collected into tubes containing 0.1 ml. sodium citrate (38 gm./100 ml. water), or 20 mg. ethylenediaminetetra#{228}cetic acid (EDTA), or 14 mg. sodium oxalate. The latter two anticoagulants are added as solutions and then the solutions are dried. Plasma was separated by centrifugation at 1500 g for 10 mm. and either analyzed within several hours or stored at _200 for subsequent analysis. Plasma (0.2 ml.) was well mixed with 4 ml. reagent-grade acetonet (Fisher Scientific Company) and centrifuged at 1500 g for 3 mm.; 3 ml. of the supernatant was transferred to a 10 X 75 glass tube (disposable),