Rapid Plasma Reagin

AsseyMethod: Agglotination
Abbrevation: R.P.R
Sector: Serology
SampleType: S
S.Vol: -
Transport: at 2-8˚c, -20˚c
Storage: 4 days at 2-8˚c for longer time at -20˚c
Test Name: Rapid Plasma Reagin
Normal Range: Normal>16%

This test is related to
Why get tested?

To see whether a person has syphilis caused by a bacteria called Treponema pallidum, and how far the disease has progressed. This information helps the doctors to choose the best possible treatment. Timely diagnosis of the infection also helps to cure the disease early and decrease the chances of complications.

When to get tested?

If you have symptoms of syphilis or
you have another Sexually transmitted disease (STD) or
you have a partner who has syphilis or
if you are pregnant or
to monitor the treatment of syphilis or
if you are involved in high risk sexual activities.

Sample required?


Blood - Most common method used for testing is doing a blood test by taking blood from your vein. Your body produces antibodies (a type of protein) when infected with syphilis. This antibody can be tested and measured in your blood to diagnose syphilis.

Swab/scrape – If you have a sore/ulcer then a swab can be taken from that to test under the microscope for the bacteria (less commonly done nowadays) or it can be tested for bacterial genetic material (PCR, polymerase chain reaction)

CSF - In certain cases, if syphilis involves the brain, doctors can put a needle through your back to tap some fluid (CSF, Cerebrospinal fluid), which can be tested for infection.

Test preparation needed?


What is being tested?

The test is looking for evidence of Treponema pallidum, the bacterium that causes syphilis. Syphilis is a sexually transmitted disease. It is easily treatable but can cause severe health problems if left untreated.

The evidence of the presence of bacteria are:

If syphilis producing bacteria enters your body then the body’s defence system (immune system) would start producing proteins against the invading bacteria to try to fight the infection. These proteins are called antibodies. In laboratories these antibodies, which are produced in response to syphilis infection can be identified and measured by tests called serological tests. Doctors can interpret this test result to find out if you are infected and if infected, how far the infection might have progressed. Doctors might need to repeat the test to confirm the diagnosis and interpret the result better.

Bacteria itself
If you have a sore, a swab or scrape may be collected to look for the bacteria under the microscope. It is called dark ground microscopy. This test is infrequently done now as it needs a lot of expertise and antibody testing is easier to do, quicker and reliable.

Bacterial genetic material
This test is called PCR (polymerase chain reaction). It looks for Treponema pallidum genetic material in a sample directly taken from the sore/ulcer. This test is only available in a few specialised (reference) laboratories in the UK.

How is the sample collected for testing?

Usually the samples are collected in a genitourinary medicine (GUM) clinic, Sexual health clinic or in a GP surgery. However it is possible for the test to be done in hospitals as well.

There are several different methods and tests for the identification of syphilis infection. A sample may be:

  • A scraping from a sore on the affected area (the cervix, penis, anus, or throat)
  • A blood sample from a vein in your arm to detect antibodies to syphilis in your blood
  • A spinal tap (lumbar puncture) may be necessary if you have late or latent stages of the disease to check for infection of the nervous system. This involves passing a needle into the back to obtain some fluid.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.