RAPID PLASMA REAGIN (RPR) CARD TEST FOR SYPHILIS
The RPR testis a sensitive, easily done screening test for syphilis. It is performed on unheated plasma or serum. Everything needed for the testis in a kit that is available commercially. This is very useful aboard ship and at small stations not equipped to do the VDRL.
Principle of the Test
The RPR test is a nontreponemal testing procedure for the serologic detection of syphilis. The RPR card antigen suspension is a carbonparticle cardiolipin antigen that detects reagin, an antibodylike substance present in the sera from syphilitic persons and occasionally in sera of persons with other acute or chronic conditions. When a specimen contains antibody, flocculation occurs with a coagglutination of the carbon particles of the RPR card antigen, which appear as black clumps against the white background of the plastic-coated card. Nonreactive specimens appear to have an even light-gray color.
Reagents
1. RPR Card Test Antigen
a. The antigen consists of cardiolipin, lecithin, cholesterol, EDTA, charcoal, Na2HPO4, KH2PO4, choline chloride (10 percent), distilled water, and the preservative thimerosal (0.1 percent) (supplied in kit).
b. Store unopened vials at 4°C. Stable to expiration date.
c. Store “in-use” antigen suspension in dispensing bottle at 4°C. Stable for about 3 months, or until expiration date if it occurs sooner.
d. Record antigen lot number and expiration date on dispensing bottle.
2. RPR Card Test Control Cards
a. The card consists of three labeled test areas containing lyophilized specimens with designated patterns of reactivity: Reactive, Reactive-Minimal-to-Moderate, and Non-reactive.
b. Store unopened foil-sealed envelopes at 4°C. Stable to expiration date.
c. Not supplied with the kit and must be purchased separately.
Equipment
1. Needle
a. Supplied in kit
b. Adjusted to deliver 60 drops, plus or minus 2 drops, per milliliter of antigen.
2. Dispensing Bottle
a. Supplied in kit
b. Used to store in-use antigen
3. Rotator—Adjusted to 100 r.p.m.
4. Dispenstir
a. Supplied in kit
b. Manufactured to dispense 0.05 ml of serum
5. Diagnostic Cards
a. Supplied in kit
b. Plastic-coated cards, with 10 rings, for testing patient specimens.
Preliminary Preparation for Testing
1. Remove antigen suspension vial and one control card envelope from the refrigerator. Allow to adjust to room temperature.
2. Resuspend contents of vial by vigorously shaking the antigen vial.
3. Snap the neck of the vial.
4. Attach the needle (provided in the kit) to a 1 milliliter tuberculin syringe. Slowly draw up into the syringe approximately 1 milliliter of the antigen suspension from the vial.
5. Hold the syringe perpendicular to the surface, and count the number of drops dispensed from a 0.5 ml volume. Allow the drops to fall into the antigen vial. The needle is accurate if 30 drops, plus or minus 1 drop, are dispensed from the 0.5 ml volume.
6. Slowly expel the remainder of antigens in the syringe back into the antigen vial.
7. Remove the needle from the syringe; place the needle on the tapered fitting of the plastic dispensing bottle (provided in kit).
8. Slowly withdraw all contents of the antigen vial by collapsing the dispensing bottle and using it as a suction device.
9. Allow the rotator to warm up for 5 to 10 minutes; adjust to 100 r.p.m.
Test Procedure
1. Open foil package and remove control card.
2. Reconstitute each control card circle with 0.5 ml of distilled water by use of a dispenstir.
