Test Overview

Test Methodology

Nontreponemal flocculation procedure (RPR).

Test Usage

Screening test for syphilis.

Reference Range*


* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

Nonspecific positive reactions may be found in SLE, malaria, infectious mononucleosis, hepatitis, leprosy, brucellosis, atypical pneumonia, typhus, and other infections. Reactive tests due to related treponemal infections (bejel, pinta, or yaws) may also occur. A reactive result in a newborn may be due to passive transfer from mother's blood.

Test Details

Days Test Performed

Monday - Friday

Analytic Time

8 hours

Soft Order Code




Rapid Plasma Reagin
Rapid Plasma Reagin, Serum
RPR, Serum
Serologic Test for Syphilis
Syphilis Antibody Screen
Syphilis Screening Test
Treponema pallidum Antibody Screen, Serum
VDRL Equivalent, Serum
Rapid Plasma Reagin
Serologic Test for Syphilis
Syphilis Screening Test
VDRL Equivalent, Serum

+ See More


Chemical Pathology

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Specimen Requirements

Offsite Collection Instructions

Collect specimen in SST tube. Centrifuge, aliquot serum into plastic vial and refrigerate.
Contaminated, lipemic or grossly hemolyzed sera should not be used because of the possibility of nonspecific reactions.

Rejection Criteria



Yellow Top Tube

Normal Volume

0.5 ml serum

Minimum Volume

0.5 ml serum

Additional Information

Reactive specimens will be titered (RPRQN) and the more specific FTA-ABS (FTA A) test will be performed for confirmation at additional charges. By ordering this test the clinician acknowledges that additional reflex testing will be performed and billed at a separate additional charge if indicated. In untreated syphilis, reactive sera are found in the chancre stage 30% after one week and 90% after three weeks. In the secondary stage, the RPR should be reactive 100% of the time, decreasing to 90% in the tertiary stage. In the latent stage and after successful treatment, the RPR may become nonreactive. The titer of antibody will vary from patient to patient. There is no direct relationship between the amount of reagin and the severity of disease. A patient's peak titer will usually occur during the secondary stage, then decrease and plateau during later stages.

Billing Information

Fee Codes

CPT Code


Reflex Fee Code

21923 RPRQN, 30942 FTA A


20507-0 (RPR), 31147-2 (RPRQN)

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