Which test is NOT considered for syphilis testing?

The polymerase chain reaction (PCR) test is indeed not typically considered a standard test for syphilis diagnosis. Syphilis is primarily diagnosed using serologic tests that detect antibodies produced in response to the infection.

Tests like the FTA-ABS (Fluorescent Treponemal Antibody Absorption) are specifically used to confirm the presence of antibodies against the Treponema pallidum bacterium, which causes syphilis. Similarly, the RPR (Rapid Plasma Reagin) and VDRL (Venereal Disease Research Laboratory) tests are non-treponemal tests that detect non-specific antibodies which can indicate the presence of syphilis, but they need to be confirmed with treponemal tests like the FTA-ABS.

In contrast, PCR is a molecular technique that amplifies the genetic material of pathogens and is used for detecting various infectious diseases. While PCR can be useful in diagnosing certain infections and is a powerful tool for identifying active infections, it is not routinely used for syphilis testing. Thus, among the provided choices, PCR is the correct option as it does not fit into the category of standard syphilis testing methods.