Western bots are a type of immunoassay in which antibodies
are used to detect and identify proteins. First sample proteins are separated
by electrophoresis on a SDS-PAGE gel. Then, the proteins are transferred onto a
nitrocellulose or nylon membrane. The membrane is then washed with a solution
containing the protein-specific antibody. Secondary antibodies, are used to
detect the presence of the primary antibody on the membrane surface. The
secondary antibody is linked to a reporter enzyme that can be used for
chemiluminescence or fluorescence detection. Assay specificity is a function of
the primary detection antibody. Assay sensitivity is a function of the type of
signal used and the detection platform.