Final answer:
The diagnosis of syphilis in a laboratory setting involves using methods such as darkfield or brightfield microscopy and serologic tests to detect the presence of the bacterium Treponema pallidum.
Step-by-step explanation:
The diagnosis of Syphilis in a laboratory setting involves several methods. Darkfield or brightfield microscopy can be used to detect the presence of the bacterium Treponema pallidum in tissue or exudate from lesions. If these methods are not available, serologic tests can be used for a presumptive diagnosis. These include treponemal and nontreponemal serologic tests, such as the Venereal Disease Research Laboratory (VDRL) and rapid plasma reagin (RPR) tests.
Confirmatory testing should be done using treponemal tests, which detect antibodies specifically for the spirochete antigens. Both treponemal and nontreponemal tests should be used, as each has limitations that can result in false positives or false negatives.