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Syphilis Confirmation Particle Agglutination (TP-PA)

Laboratory Fee Schedule

Procedure: MCS0318A

CPT: 86780

Synonym(s): Treponema pallidum particle agglutination, Treponemal antibody, Syphilis antibody, TP-PA, TPPA
Requisition Form G-2A
Test Description Qualitative gelatin particle agglutination assay for the detection of antibodies to Treponema pallidum in human serum. 
Pre-Approval Needed N/A
Supplemental Information Required N/A
Supplemental Form(s) N/A
Performed on Specimens from (sources) Human
Sample/Specimen Type for Testing Serum
Minimum Volume/Size Required 100 µL
Storage/Preservation Prior to Shipping
  • Store at 2° to 8°C for 5 days.
  • For long term storage, store frozen at -20°C or colder.
Transport Medium N/A
Specimen Labeling
  • Two patient-specific identifiers required on specimen (e.g., patient full name, date of birth, medical record number). 
  • Three patient identifiers are preferred. 
  • Patient identifiers on specimen label must exactly match identifiers on submission form (e.g., abbreviated name on label and full name on form is not acceptable). 
  • Additional DSHS Laboratory specimen labeling guidelines available online here. 
Shipping and Specimen Handling Requirements
  • Ship according to Dangerous Goods Regulations, IATA, and/or CFR 49. 
  • Category B Biological Substance, UN3373 shipping requirements apply.  
  • Handle as infectious agent using universal precautions.  
  • Triple contain in accordance with federal shipping regulations for infectious agents.  
  • Submitters are responsible for packaging and shipping specimens according to regulatory requirements.  
  • If specimens will arrive at the Lab within 5 days of collection, refrigerate at 2°C –8°C and ship overnight on cold packs. 
  • If specimens will arrive at the Lab more than 5 days after date of collection, freeze at -20°C or below, and ship overnight on dry ice.
  • Additional DSHS Laboratory specimen shipping guidelines online here.   
Method Particle agglutination assay
Turn-around Time 4 working days.
Interferences/Limitations
  • TP-PA may be reactive in persons from areas where yaws or pinta was, or is, endemic. 
  • Serum may be frozen and thawed only once prior to testing.
Common Causes for Rejection
  • Insufficient specimen quantity.
  • Unacceptable specimen type or source.
  • Improper shipping conditions.
  • Expired media or collection container.
  • Expired reagents/media/collection container. 
  • Discrepancies between G-2A submission form and specimen label. 
  • Missing/incomplete/illegible submission form or label.
Additional Information
  • A reactive TP-PA test indicates past or present infection and usually remains reactive for life. 
  • Specimens with inconclusive TP-PA results should be retested. Collect a second specimen in two weeks for TP-PA testing to confirm results.