Methodology
Chromogenic, Photometric Clot Detection
Synonyms
FVIII Bethesda Inhibitor; Factor VIII Inactivity; Inhibitor APTT; Factor 8 Inhibitor Evaluation
Specimen Type
Plasma
Performing Lab
Quest Diagnostics San Juan Capistrano
Epic ID
LAB01206
Lab Test Days
Sunday, Tuesday, Thursday
Standard TAT
2-5 Days
Collection Information
Specimen Required
(three-four) 1.8 mL or (two-three) 2.7 mL Blood
Container Type
Light Blue (Sodium Citrate)
Processing Information - Lab Use Only
Transport Temperature
Frozen-Only
Specimen Stability
Room Temp=Unacceptable; Refrigerated=Unacceptable; Frozen=14 Days
Test Volume Required
(two-three) 2 mL Platelet-Poor Plasma
Minimum Test Volume
(two-three) 1 mL Platelet-Poor Plasma
Processing Instructions
Centrifuge light blue-top tube 15 minutes at approx. 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer an dplace into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcl). Freeze immediately and send frozen.
Included Tests
Factor VIII Inhibitor, Chromogenic Screen. Factor VIII Activity, Clotting. If Factor VIII Inhibitor, Chromogenic Screen is Positive, then Nijmegen Assay will be performed at an additional charge (CPT code(s): 85335).
CPT Codes
85240, 85335
Revised
6/10/26
Initials
IM