How immunofluorescence detects antigens and antibodies: the fluorophore-labeled antibody principle, the key difference between direct (DFA) and indirect (IFA) methods, and where ea...
How the indirect fluorescent antibody (IFA) test uses two antibodies to detect antibodies in patient serum (and antigens in cells). Principle, procedure, syphilis example, and why...
How a fluorescence microscope makes labeled organisms glow against total darkness, and why it's replaced ordinary staining for TB screening and several other diagnostic tests.
How the direct fluorescent antibody (DFA) test detects antigen directly in a specimen using one labeled antibody. Principle, step-by-step procedure, apple-green result, and the key...
How to interpret an FTA-ABS result: what reactive-plus-reactive-RPR confirms, why FTA-ABS stays positive for life, why it cannot monitor treatment, and how it now compares to TPPA...
