Ordering Recommendation

Acceptable screening panel for common inherited thrombophilias.




Electromagnetic Mechanical Clot Detection/Quantitative Enzymatic Assay/Polymerase Chain Reaction/Fluorescence Monitoring




2-7 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation

Fasting preferred. Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.


Lt. blue (sodium citrate) AND lavender (EDTA) or pink (K2EDTA) AND serum separator tube, green (sodium or lithium heparin), or EDTA (K2 or K3).

Specimen Preparation

Serum Separator Tube, Green (sodium or lithium heparin), or EDTA (K2 or K3) must be centrifuged and serum or plasma separated within 1 hour of collection. Transfer 1 mL centrifuged serum or plasma to ARUP Standard Transport Tube and label centrifuged tube for homocysteine testing. (Min: 0.5 mL) AND Transport two 2 mL aliquots platelet-poor plasma (sodium citrate) (Min: 1 mL/aliquot) AND Transport 5 mL whole blood (EDTA). (Min: 1 mL)

Storage/Transport Temperature

Light blue (sodium citrate):  CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.
Lavender whole blood and Serum or Green (sodium or lithium heparin): Frozen.

Unacceptable Conditions

Specimens collected in any tube type not listed above and frozen specimens in glass collection tubes.


Light blue (sodium citrate): Ambient: Unacceptable; Refrigerated: Unacceptable; Frozen: 2 weeks
Lavender whole blood:
Ambient: 7 days; Refrigerated: 1 week; Frozen: 1 month
Serum, Green (sodium or lithium heparin), or EDTA (K2 or K3): Ambient: 4 days; Refrigerated: 1 month; Frozen: 10 months

Reference Interval

Test Number
Reference Interval
  Partial Thromboplastin Time 24-35 seconds
  Factor VIII, Activity
Reference Interval (%)
0-6 years 56-191
7-9 years 76-199
10-11 years 80-209
12-13 years 72-198
14-15 years 69-237
16-17 years 63-221
18 years and older 56-191

  Homocysteine, Total 0-15 µmol/L, for both male and female
  APC Resistance 2.00 or greater

Interpretive Data

Ratios less than 2.00 suggest APC resistance. This method uses factor V deficient plasma; therefore, APC resistance due to a nonfactor V mutation will not be detected. Extreme factor V deficiency or presence of direct oral anticoagulants (DOACs) may cause an unreliable ratio. Elevated total homocysteine (tHcy) concentrations may be associated with vitamin B12 deficiency, folate deficiency, or inherited disorders of methionine metabolism. tHcy may also be used as a weak-graded risk factor for cardiovascular disease or stroke.

Compliance Category



If APC resistance is normal, then no further testing will be added. If APC resistance is low, or if a valid result cannot be obtained for the APC portion of the profile, then Factor V Leiden by PCR will be added. Additional charges apply. False elevations of plasma or serum homocysteine may occur if the plasma or serum is not promptly separated from the cells at the time of collection.

Hotline History


CPT Codes

85730; 85240; 83090; 81240; 85307; if reflexed, add 81241


Component Test Code* Component Chart Name LOINC
0030052 Thrombosis Interpretation 48767-8
0030095 Factor VIII, Activity 3209-4
0030193 APC Resistance 13590-5
0030194 Factor V Leiden by PCR 21668-9
0030235 Partial Thromboplastin Time 14979-9
0056060 Prothrombin (F2) G20210A Variant 24475-6
0099869 Homocysteine, Total 13965-9
2001308 FACV REF Specimen 31208-2
2001334 PT PCR Specimen 31208-2
* 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.


  • Activated Protein C Resistance
  • APC Resistance
  • APCR
  • F2 G20210A mutation
  • F8 Activity
  • Factor V Leiden
  • Factor V Leiden Functional Assay
  • Factor V Leiden PCR
  • Factor VIII, Activity
  • FVL
  • Hypercoag
  • Hypercoagulable Panel
  • Protein C Resistance
  • Prothrombin mutation
  • prothrombin time
  • PTT
  • total homocyteine
Thrombotic Risk, Inherited Etiologies (Most Common) with Reflex to Factor V Leiden (Change effective as of 02/21/23: Refer to 0030095, 0030192, 0030235, 0056060, 0099869)