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Test Code 4389 Factor VIII, Plasma

Performing Laboratory

Barnes-Jewish Hospital Laboratory


Absorbance measurement, Clot signature formation

Literature References:

HemosIL SynthASil (0020006800) package insert issued 06/2017, Instrumentation Laboratory.

Specimen Requirements

Specimen Type: Plasma

Container/Tube: Light-blue top (citrate)

Specimen Volume:  Full tube

Specimen Minimum Volume:  Full tube

Collection Instructions:

1. Draw a discard tube prior to light-blue top (citrate) tube.
2. Tube should remain stoppered.
3. Do not centrifuge.
4. Clotted blood or an insufficient specimen is not acceptable.
5. Avoid hemolysis and heparin contamination of specimen.

6. Blood should not be drawn through an indwelling catheter or an A-V shunt.


Analyte Stability:

4 hours at 18° C to 24° C if the top has not been removed.

2 hours at 18° C to 24° C after the top has been removed.


Additional Information: If the patient is a hospital patient and the hematocrit is >55%, call Barnes-Jewish Hematology Laboratory at 314-362-5203 for instructions.

Day(s) Test Set Up

Monday through Sunday
Turnaround Time:
STAT: 2 hours after receipt in laboratory
Routine: 2-4 hours after receipt in the laboratory

Reference Values


Literature References:

1. Colman RW, Hirsch J, Marder VJ, Salzman EW. Hemostasis and thrombosis, basic principles and clinical practice. Philadelphia:  J.B. Lippincott Co., 1982.
2. Thompson AR, Harke LA. Manual of hemostasis and thrombosis, Edition 3. Philadelphia:  F.A. Davis Co., 1983.

Test Classification and CPT Coding


Additional Information

For BJH Laboratory Use Only
Analyte Stability:

4 hours at 18° C to 24° C if the top has not been removed.
2 hours at 18° C to 24° C after the top has been removed.

Specimen cannot be refrigerated or frozen.

Laboratory Processing Instructions:

Test performed in BJH Hematology.

Specimen Transport Temperature

Ambient/Refrigerate NO/Frozen NO

Ambient Whole Blood:  4 hours at 18° C to 24° C

Specimen cannot be frozen

LOINC Code Information

Name LOINC Code
Factor VIII, Plasma 3208-6