Sign in →

Test ID EMICZ Emicizumab, Modified One Stage Assay Factor VIII, Plasma

Ordering Guidance

For monitoring factor VIII infusions or diagnosing hemophilia, order F8A / Coagulation Factor VIII Activity Assay, Plasma.

Necessary Information

If priority specimen, mark request form, give reason, and request a call-back.

Specimen Required

Patient Preparation: It is preferred that the patient avoid infusions of factor VIII concentrates for at least 12 to 24 hours preceding sample collection for this assay.

Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial (polypropylene preferred)

Specimen Volume: 1 mL

Collection Instructions:

1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing

2. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.

3. Aliquot plasma into a plastic vial leaving 0.25 mL in the bottom of centrifuged vial.

4. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, ≤-40° C.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.

Useful For

Monitoring compliance or potential development of an antidrug antibody


This assay is not indicated for monitoring factor VIII infusions or for making a diagnosis of hemophilia.

Method Name

Optical Clot-Based

Reporting Name

Emicizumab, modified OSA FVIII, P

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Na Cit Frozen 42 days

Reference Values

<1 mcg/mL

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
EMICZ Emicizumab, modified OSA FVIII, P 99614-0


Result ID Test Result Name Result LOINC Value
EMICZ Emicizumab, modified OSA FVIII, P 99614-0

Day(s) Performed

Monday through Friday

Report Available

1 to 7 days