Treponema pallidum Antibody (FTA-ABS), Serum, IgG by IFA with Reflex to Treponema pallidum Antibody by TP-PA
Ordering Recommendation
Not an optimal reflex test. Treponema pallidum Antibody by TP-PA (0050777) is preferred.
Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Particle Agglutination
1-4 days  
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
Serum separator tube.  
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)  
Storage/Transport Temperature
Unacceptable Conditions
CSF, plasma, or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.  
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)  
Reference Interval
Test Code Components Reference Interval
 T.Pallidum Ab, IgG (FTA-​ABS) Nonreactive
0050777 Treponema pallidum Antibody by TP-​PA Nonreactive
Interpretive Data
The Fluorescent Treponema Antibody (FTA) is recommended for follow-up of reactive nontreponemal tests for syphilis, and as a single test in patients suspected of late syphilis. The FTA may be used to resolve discrepancies between laboratory results and clinical impressions. FTA tests for syphilis may be falsely positive in some cases of systemic lupus erythematosus, pregnancy, and leprosy.

The FTA test is not recommended for cerebrospinal fluid specimens. For CSF specimens, the VDRL-CSF test is recommended.

Inconclusive results will be repeated by TP-PA to aid the physician in diagnosis.  Inconclusive final reports indicate the initial specimen submitted has been tested twice and cannot be interpreted as either reactive or nonreactive. If it is the second specimen submitted on a patient and the report is again inconclusive, it is impossible to state definitively that the patient does or does not have syphilitic infection.

Reflex will only happen when the FTA is found to be inconclusive. Additional charges apply.
CPT Code(s)
86780; if reflexed, add additional 86780
Component Test Code*Component Chart NameLOINC
0050477T.Pallidum Ab, IgG (FTA-ABS)17726-1
* 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.
  • Fluorescent Treponemal Antibody Absorption Test
  • Fluorescent Treponemal Antibody, Serum, IgG
  • FTA, Serum
  • FTA-ABS Reflex to TP-PA
  • Syphilis Ab FTA-ABS reflex to TP-PA
  • T pallidum Ab FTA-ABS reflex to TP-PA
  • T pallidum Ab TP-PA
  • Treponema Antibody, Serum
  • Treponema pallidum Antibody FTA-ABS, Serum
  • Treponema pallidum Particle Agglutination Assay