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Test Code SYPGR Syphilis IgG Antibody with Reflex, Serum

Important Note

This test is only orderable by automatic reflex after a positive Syphilis Screen, with the exception of neonates (<30 days).

Reporting Name

Syphilis IgG Ab w/Reflex, S

Useful For

Aids in the diagnosis of active Treponema pallidum infection


Routine prenatal screening

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
RRPR Rapid Plasma Reagin w/ Reflex, S No No
RTPPA Syphilis Ab, TP-PA, S No No
RRPRQ RPR Titer, S No No

Testing Algorithm

If syphilis IgG is positive, then rapid plasma reagin (RPR) will be performed at an additional charge.


If RPR is positive, then RPR titer will be performed at an additional charge.


If RPR is negative, then syphilis antibody will be performed at an additional charge.


See Syphilis Serology Algorithm in Special Instructions.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 1 mL

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Special Instructions

Reference Values


Day(s) and Time(s) Performed

Monday through Saturday; 9 a.m.

Seattle Children's Hospital Note:

TAT: 3 - 6 days

CPT Code Information

86780-Syphilis antibody

86592-Rapid Plasma reagin (if appropriate)

86780-Syphilis Antibody by TP-PA (if appropriate)

86593-Rapid Plasma Reagin Titer (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SYPGR Syphilis IgG Ab w/Reflex, S 47238-1


Result ID Test Result Name Result LOINC Value
SYPGR Syphilis IgG Ab w/Reflex, S 47238-1

Method Description

The BioPlex Syphilis IgG is a multiplex flow immunoassay performed on the BioPlex 2200 System (Bio-Rad Laboratories, Hercules, CA). Three types of dyed beads are coated with recombinant proteins associated with Treponema pallidum (15kDa, 17kDa and 47kDa). An aliquot of patient sample, sample diluent, and bead reagent are combined in a reaction vessel, and the mixture is incubated at 37 degrees C. After a wash cycle, antihuman IgG antibody conjugated to phycoerythrin (PE) is added to the dyed beads, and this mixture is incubated at 37 degrees C. Excess conjugate is removed in another wash cycle and beads are resuspended in wash buffer. The bead mixture is then passed through a flow-based detector and identified according to the fluorescence emitted, which is specific to the internal dye composition of the microsphere. The amount of antibody bound to the capture antigen is then determined by measuring the fluorescence of the attached PE. Raw data is calculated in relative fluorescence intensity (RFI).(Package insert: BioPlex 2200 System Syphilis IgG [T.pallidum], Bio-Rad Laboratories Clinical Diagnostic Group, Hercules, CA)


If the IgG result is positive, a rapid plasma regain (RPR) is automatically performed. The RPR test is a macroscopic screening assay done with unheated serum. Reagin reacts with nontreponemal 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)


The Serodia TP-PA test is based on the agglutination of colored gelatin particle carriers sensitized with Treponema pallidum (Nichols Strain) antigen. Serum samples are serially diluted in microplate wells. Sensitized gelatin particles are added to respective wells and the contents of the plate mixed.  The mixture is incubated for 2 hours at room temperature. Serum containing specific antibodies will react with the antigen-sensitized colored gelatin particles to form a smooth mat of agglutinated particles in the microplate well. A compact button formed by the settling of the non-agglutinated particles characterizes negative reactions. The agglutination patterns are read visually to determine interpretation.(Package insert: Serodia -TP PA, Fujirebio Diagnostics, Inc., Tokyo, Japan.)

Reject Due To


Mild OK; Gross reject


Mild OK; Gross reject




Heat-inactivated specimen

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

Method Name

SYPGR: Multiplex Flow Immunoassay

RRPR/RRPRQ: Flocculation/Agglutination

RRPR: Flocculation

RTPPA: Particle Agglutination