Test Catalog

Test ID: RPRRT    
Rapid Plasma Reagin Screen Response to Therapy, Serum

Method Description Describes how the test is performed and provides a method-specific reference

For the initial automated rapid plasma reagin (RPR) screen, cardiolipin antigen-coated fluoromagnetic beads with unique fluorescent signatures are used to identify nontreponemal reagin antibodies in human serum. Dyed microparticle beads are coated with cardiolipin antigen. The BioPlex 2200 System combines an aliquot of patient sample, sample diluent, and bead reagent into a reaction vessel. The mixture is incubated at 37 degrees C. After a wash cycle, antibodies conjugated to phycoerythrin (PE) are added to the dyed beads, and this mixture is incubated at 37 degrees C. The excess conjugate is removed in another wash cycle, and the beads are resuspended in wash buffer. The bead mixture then passes through the detector. The identity of the dyed beads is determined by the fluorescence of the dyes, and the amount of nontreponemal reagin antibodies captured by the reagin is determined by the fluorescence of the attached PE. Raw data is calculated in relative fluorescence intensity (RFI).(Package insert: BioPlex 2200 Syphilis Total and RPR. Bio-Rad; 06/2017)


If the RPR screen is reactive, an RPR titer test is performed reflexively using a manual method. The RPR titer test is a macroscopic screening assay done with unheated serum. Reagin reacts with non-treponemal antigen containing colloidal charcoal particles. This reaction results in a visual flocculation of the black particles against the white card background. The test yields a positive or negative result, and all positive samples are titered to determine the highest positive dilution.(Huber TW, Storms S, Young P, et al: Reactivity of microhemagglutination, fluorescent treponemal antibody absorption, Venereal Disease Research Laboratory, and rapid plasma reagin tests in primary syphilis. J Clin Microbiol. 1983 Mar;17[3]:405-409; Kaur G, Kaur P: Syphilis testing in blood donors: an update. Blood Transfus. 2015 Apr;13[2]:197-204. doi: 10.2450/2014.0146-14)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Saturday

Report Available The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 4 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location Indicates the location of the laboratory that performs the test