Methodology
Clotting Assay
Synonyms
Factor 8 Activity; F8; FVIII Activity
Performing Lab
RCHSD Coagulation (Go-Live 1/6/25)
Epic ID
LAB1846
Lab Test Days
Monday and Thursday (11am cutoff)
Standard TAT
4 Hours (Monday and Thursday before cutoff); 1-4 Days
Collection Information
Specimen Required
(one) 1.8 mL or (one) 2.7 mL Blood
Container Type
Sodium Citrate (Blue-Top) Tube
Collection Instructions
1.8 mL blue top vacutainers should contain a minimum of 1.62 mL of whole blood. 2.7 mL blue top vacutainers should contain a minimum of 2.43 mL of blood (no more than a 10% variation from the ideal). If the patient's hematocrit is greater than 55%, the volume of anticoagulant must be adjusted to compensate for a decreased plasma volume.
Processing Information - Lab Use Only
Transport Temperature
Frozen Only
Specimen Stability
Room Temp: 4 Hours; Refrigerated: Unacceptable; Frozen: 15 Days (-20) or 1 Month (-80)
Rejection Criteria
Clotted, moderate or grossly hemolyzed; Underfilled or overfilled vacutainers; Any specimen drawn using a heparinized syringe; Any unlabeled or improperly labeled or identified specimen; Any specimens that were transported under conditions outside of the acceptable temperature; Any specimens that were received after the acceptable time range
Test Volume Required
1 mL Plasma
Minimum Test Volume
0.5 mL Plasma
Processing Instructions
Processing to load on centrifuge and Hematology staff to process specimen for testing or storage. Separate plasma from cells within 4 hours of collection and transfer plasma to a screw-cap tube. DO NOT USE SNAP-CAP TUBES. Place plasma in -80 freezer ASAP.
CPT Codes
85240
Revised
1/6/25
Initials
SA