APA Dictionary of Psychology

an immunofluorescent technique to diagnose syphilis. The patient’s serum is placed on a slide with the bacterium (Treponema pallidum) that causes syphilis. If the antibodies to syphilis are present in the serum, they will react to the bacteria, yielding a positive test result. The addition of a fluorescent chaser renders the reaction visible so it can be identified when the sample is examined under a fluorescence microscope.