Ordering Recommendation

Evaluate the cause of an isolated prolonged partial thromboplastin time (PTT) in a patient who is not currently bleeding.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation

Transfer 2 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)

Storage/Transport Temperature

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Serum. EDTA plasma, clotted or hemolyzed specimens.

Remarks
Stability

Ambient: 4 hours; Refrigerated: Unacceptable; Frozen: 2 weeks

Methodology

Electromagnetic Mechanical Clot Detection

Performed

Mon-Sat

Reported

1-3 days

Reference Interval

58-166%

Interpretive Data



Compliance Category

Standard

Note

Hotline History

N/A

CPT Codes

85280

Components

Component Test Code* Component Chart Name LOINC
0030115 Factor XII, Activity 3232-6
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Coagulation Factor XII Activity Assay, Plasma
  • Factor X11a
  • Hageman factor
  • Hageman Factor (Contact Factor)
  • Intrinsic Factor Proteins
  • Intrinsic Factors
  • Surface Factor
Factor XII, Activity