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Factor VIII (8) Antigen

Test Summary

This test is an immunoassay for the quantitative determination of Factor VIII antigen in human plasma and Factor VIII concentrates. The biological importance of Factor VIII is demonstrated in Hemophilia A. Some hemophiliacs produce a protein that is partially or totally inactive. In these patients a low Factor VIII activity is seen but the antigen level is normal or near normal.

Aliases

  • Antigenic Factor VIII

Specimen Collection

Special Instructions

See Link and Print "Drug List for Special Coagualtion Tests"

Preferred Specimen

1 plastic (2.7mL) completely filled 3.2% Sodium Citrate (light blue top) tube

Minimum Volume

2 Frozen Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)

Instructions

Use standard venipuncture and disposal techniques.

Collect the required quantity of Sodium Citrate (light blue top) tubes.

If unable to process specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1.
Sodium Citrate (light blue top) tube(s): Process immediately (stable only 4 hours), following instructions below:
Note: We recommend aliquot tubes to be made of polypropylene plastic as this material is safe to freeze at <-70 degrees C.
1. Centrifuge capped Sodium Citrate (light blue top) tubes at 3000 rpm for 10 minutes, or at speed and time required to consistently produce Platelet Poor Plasma (<5/kmm3).
2. Carefully remove the plasma from all Sodium Citrate (light blue top) tubes; avoid disturbing the WBC/buffy coat, and combine all plasma into a 15mL plastic conical centrifuge tube.
Note: If the plasma shows any hemolysis, it must be recollected.
3. Centrifuge the plasma in the 15mL plastic conical centrifuge tube for a second time as in step 1.
4. In one smooth motion, carefully and quickly pour the centrifuged plasma into a second 15mL plastic conical centrifuge tube. A small amount of plasma along with a red cell button should remain on the bottom of the original conical tube if the pour was executed correctly. Note: This quick-pour method prevents platelet transfer and contamination.
5. Aliquot at least 1mL of plasma into each aliquot tubes labeled “plasma.” Refer to the Minimum Volume section above for the number of aliquots required per test.
6. Finally, place all aliquots into a <-20°C freezer within 4 hours.
Note: Aliquots must remain frozen until they are picked up by the CompuNet courier. Call CompuNet transportation department if frozen specimen boxes are needed.

Patient Preparation

N/A

Storage

Whole blood Sodium Citrate (light blue top) tube(s)
OR
Frozen -Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)

Transport Temperature

Frozen Sodium Citrate plasma

Specimen Stability

  • Room Temperature: Whole blood Sodium Citrate (light blue top) tube <
  • 4 hours
  • Refrigerated: Unacceptable for Sodium Citrate (light blue top) tube whole blood or capped plasma aliquots
  • Frozen: Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended) <
  • 30 days at &le
  • -20oC

Limitations

Anti-Coagulant medications
Rheumatoid Factor
Heterophilic Antibodies

Other Acceptable Specimens

N/A

Unacceptable Specimens

Rejected for hemolysis, clotted, improper fill, incorrect specimen type, thawed frozen aliquots, refrigerated plasma or blood, expired test tubes, >4 hours old if not processed into separated frozen plasma vials.

Order Code

F8AG

EPIC (Premier) Code

LAB5846

Includes

N/A

CPT Code

  • 85244

Billing Code

  • 300281

CPT Statement

Methodology

ELISA

FDA Status

FDA approved

Physician Attestation of Informed Consent

N/A

Testing Laboratory

CompuNet Clinical Laboratories, LLC
2308 Sandridge Drive
Moraine OH, 45439

Department

Hematology

Reference Range

See Report by age

Setup Schedule / Expected Turnaround Time

Monday; SCOAG; Report available: 1 - 6 days

Specimen Collection

Special Instructions

See Link and Print "Drug List for Special Coagualtion Tests"

Preferred Specimen

1 plastic (2.7mL) completely filled 3.2% Sodium Citrate (light blue top) tube

Minimum Volume

2 Frozen Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)

Instructions

Use standard venipuncture and disposal techniques.

Collect the required quantity of Sodium Citrate (light blue top) tubes.

If unable to process specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1.
Sodium Citrate (light blue top) tube(s): Process immediately (stable only 4 hours), following instructions below:
Note: We recommend aliquot tubes to be made of polypropylene plastic as this material is safe to freeze at <-70 degrees C.
1. Centrifuge capped Sodium Citrate (light blue top) tubes at 3000 rpm for 10 minutes, or at speed and time required to consistently produce Platelet Poor Plasma (<5/kmm3).
2. Carefully remove the plasma from all Sodium Citrate (light blue top) tubes; avoid disturbing the WBC/buffy coat, and combine all plasma into a 15mL plastic conical centrifuge tube.
Note: If the plasma shows any hemolysis, it must be recollected.
3. Centrifuge the plasma in the 15mL plastic conical centrifuge tube for a second time as in step 1.
4. In one smooth motion, carefully and quickly pour the centrifuged plasma into a second 15mL plastic conical centrifuge tube. A small amount of plasma along with a red cell button should remain on the bottom of the original conical tube if the pour was executed correctly. Note: This quick-pour method prevents platelet transfer and contamination.
5. Aliquot at least 1mL of plasma into each aliquot tubes labeled “plasma.” Refer to the Minimum Volume section above for the number of aliquots required per test.
6. Finally, place all aliquots into a <-20°C freezer within 4 hours.
Note: Aliquots must remain frozen until they are picked up by the CompuNet courier. Call CompuNet transportation department if frozen specimen boxes are needed.

Patient Preparation

N/A

Storage

Whole blood Sodium Citrate (light blue top) tube(s)
OR
Frozen -Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)

Transport Temperature

Frozen Sodium Citrate plasma

Specimen Stability

  • Room Temperature: Whole blood Sodium Citrate (light blue top) tube <
  • 4 hours
  • Refrigerated: Unacceptable for Sodium Citrate (light blue top) tube whole blood or capped plasma aliquots
  • Frozen: Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended) <
  • 30 days at &le
  • -20oC

Limitations

Anti-Coagulant medications
Rheumatoid Factor
Heterophilic Antibodies

Other Acceptable Specimens

N/A

Unacceptable Specimens

Rejected for hemolysis, clotted, improper fill, incorrect specimen type, thawed frozen aliquots, refrigerated plasma or blood, expired test tubes, >4 hours old if not processed into separated frozen plasma vials.

Billing

CPT Code

  • 85244

Billing Code

  • 300281

CPT Statement

Result Information

Methodology

ELISA

Testing Laboratory

N/A

Reference Range

See Report by age

Setup Schedule / Expected Turnaround Time

Monday; SCOAG; Report available: 1 - 6 days