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Test Code F8 INH SC Factor VIII Inhibitor Screen

Important Note

Method is affected by improper collection, processing or storage. Available stat if pre-approved.

Clinical System Name

Factor 8 Inhibitor Screen


Anti Factor 8 - Screen
Factor 8 Inhibitor Screen

Sample Requirements

Specimen: Whole Blood

Container(s): Lt. Blue/Citrate

Preferred Vol: (3) 1.8 mL or (1) 2.7 mL

Minimum Vol:  (1) 1.8 mL



Processing Instructions

Reject due to: Clotted, Hemolyzed, Insufficient quantity, and  Improper collection.

Spin: N

Aliquot: N

Temp: RT

Storage location:  Core 6 Freezer  ( -70 C) Send Out rack.


Note:   Deliver blood to Core Coag bench.  Coag Technologist will process. Specimen should be centrifuged within  1hour of collection. Spin whole blood, remove plasma. Transfer upper 3/4 layer of plasma to plastic tube and make 2 aliquots  0.6 mL, affix large label and store in -70 freezer, Send Out rack.


Off-site collection: Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volumel. Use of a Vascular Access Device for the collection of coag testing is not recommended. If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the Lt Blue/Citrate tube by use of the blood transfer device.

Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze 2 aliquots of 0.6 mL plasma in plastic tubes at -70C.

Ship frozen on dry ice.


Specimen Type Temperature Time
Citrated platelet-poor plasma Room temp N
  Refrigerated N
  Frozen Y



STAT Performed TAT
Y, with approval  Drawn daily; performed  M - F 5 d


Performing Laboratory

Harborview Medical Center



Harborview Medical Center

Room GWH47; 523 9th Ave
Seattle, WA 98104

Phone Number: (206) 744-3451



Reference Range


None detected

Values reported in Bethesda units.


Method: None specified

Analytical Volume: None specified


CPT Codes



Send Out Instructions


Reference Test Name: Factor VIII Inhibitor Screen
Reference Test Number: F8INSC
Instructions: See protocol for stat sendouts. If not ordered stat, send out Mon - Fri with the UW/HMC courier.Ship on dry ice. Use a yellow UW/HMC General request form. Keep the bottom copy for our lab records.