Serological Assays

Serological techniques are often used for studying viruses in a liquid sample. These techniques include complement fixation, immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) (Cann 2012). While they are all based on antigen–antibody (immune) reactions, they differ in their detection methods. For example, complement fixation measures the haemolysis of red blood cells in the presence of antigen–antibody complexes. In contrast, immune complexes in immunofluorescence and ELISA are detected through fluorescent emission and enzymatic reaction, respectively (Fig. 6.1). This section will describe the use of ELISA as it is one of the most popular techniques used to detect viruses in liquid samples such as blood.