Factor XIII Screen

Profile or Test Panel
Method Clot Solubility
Test Information Factor XIII forms covalent cross links between fibrin chains. In the absence of Factor XIII, the fibrin clot will be dissolved by 5 M urea which disrupts the hydrogen bonds. This assay will be abnormal only if the factor XIII level is <2-5%. Hereditary factor XIII deficiency, an autosomal recessive disorder, should be suspected in a patient with delayed post-surgical or traumatic bleeding, unexplained CNS hemorrhage.  Women with severe FXIII deficiency have difficulty maintaining pregnancy.
Additional Test Information Normal Range:  insoluble in urea
Sample Requirements Whole Blood:  3.2% Sodium Citrated (blue top)  OR
Frozen Plasma
Requested Volume Two 5 ml 3.2 sodium citrated (blue top) tubes as whole blood  OR
Frozen plasma in 4 X 1mL aliquots in plastic tubes 
Minimum Volume or Pediatric volume Frozen Plasma:  at least 0.5ml in 2 plastic tubes.  
Sample Information Whole blood is preferred for testing but if it is not possible to send whole blood tubes TO ARRIVE HERE WITHIN 3 HOURS of collection then send frozen plasma.  To prepare plasma centrifuge blue top tubes at 1500g for 15 minutes and remove the plasma and centrifuge a second time at 1500g for an additional 15 minutes.  Aliquot approximately 1 ml of plasma into 4 plastic tubes, and freeze.  
Shipping Information Whole Blood:  Send at ambient temperature (18-25C) and must be received within the lab in less than or equal to 3 hours after collection.
Frozen Plasma:  send on dry ice 

Send samples to:

Bloodworks Northwest
Attn: Hemostasis Laboratory
921 Terry Ave
Seattle, WA 98104

For additional information, please see Ordering Information
Requisition Form RFT- Hemostasis Reference Laboratory
Transaction Code 3200-07
CPT Codes 85291
Turn around Time (analytic time) 5 Business Days
Report/ Results Fax number required to receive report