Serology – an overview
The basis for all serology tests is the antigen-antibody reaction. While most are for the detection of antibodies, some serology tests detect antigen, not antibody.
Antigen detection tests are commonly used to detect antigens from organisms like viruses, bacteria, fungi and parasites, often because isolating these microbes may be more difficult, expensive or insensitive.
Antigen detection tests for common pathogens are increasingly being replaced by PCR, but, for less common pathogens, antigen detection tests may still be simpler and more readily available.