UCSF Navigation Bar

UCSF Departments of Pathology & Laboratory Medicine Home Page

Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

Internal Resources

Click here for more information about laboratory operations and procedures

If you have additional questions regarding this test, please call: 415-353-1667

Search Our Test Menu

Factor 13 Activity

Item Value
Approval req'd? No
Available Stat? No
Test code F13A
Test group Factor XIII
Performed by Quest
Sendout? Yes
Method Chromogenic
Collection Instructions 1. Check the expiration date on the label of the blue top vacutainer before drawing the patient.

2. For blood collection in a sodium citrate blue top, the tube must be filled to above the Minimum Fill Indicator on the tube. It is crucial to wait and allow the tube to stop filling before removing it from the needle.

3. With use of a butterfly needle, draw about 1 cc using a separate blue top to remove air from tubing, discard the first tube and then draw a second blue top tube filled to the full extent of the vacuum.

4. Tubes should not be filled past the Maximum Fill dashed line by either using a syringe or removing the tube cap.

Avoid hemolysis. Deliver immediately to the laboratory.

For patients with Hct's ≥ 55% please contact Hematology (Parnassus: 3-1747, Mission Bay: call 6-0194) to obtain blue top tubes with adjusted citrate volumes in order to maintain the proper citrate to plasma ratio for coagulation studies.
Container type Blue top filled to full extent of vacuum
Amount to Collect 2.7 mL blood
Sample type Citrated plasma
Preferred volume 1 mL plasma
Min. Volume 0.3 mL plasma
UCSF Rejection Criteria Samples collected in outdated blue top vacutainer. Over-filled or under-filled tubes may be rejected Hemolyzed
Processing notes Deliver sample to Hematology ASAP for processing.

Separate and freeze plasma at -20C. Ship frozen. Order Quest #14461X.

For Brown and Toland patients (BTMOLT), ship the plasma on dry ice to LabCorp, test code 276937.
Ref Lab Rejection Criteria Thawed or hemolyzed sample
Units %
Normal range 57-192%
Synonyms FSF; Fibrin stabilizing factor; Urea Clot Solubility Assay; Factor 13; F13; FXIII; Factor XIII
Stability Factor assays should generally be performed within four hours of specimen collection or the plasma frozen; the latter is stable for 2 weeks at -20C or 6 months at -70C.
Turn around times 7-10 days
Additional information Assay values reported down to 3%.

Low Factor XIII levels ie., < 15% may cause a bleeding disorder and levels < 2% have been associated with spontaneous intercranial hemorrhage.

This assay replaces the previously offered Urea Clot Solubility assay that was discontinued 8/1/07.

This test is performed at Quest using a kit that has not been approved or cleared by the FDA. The analytical performance characteristics of this test have been determined by Quest Diagnostics Nichols Institute, San Juan Capistrano. This test should not be used for diagnosis without confirmation by other medically established means.
CPT coding 85290-90
LOINC code 27815-0
Last Updated 1/29/2015 4:23:09 PM
Entry Number 369
UCSF home page UCSF home page About UCSF Search UCSF UCSF Medical Center