ABSTRACT
Immunological techniques take advantage of the specificity and sensitivity of the antigenantibody reaction of mammalian systems. Antigens are substances which elicit an immune response in a host animal. Because antibodies can be produced to almost any organic compound that is considered "foreign" to the host, the possibilities for generating specific probes are great. For example, if an antibody directed against a bacterial strain is produced in a rabbit host, the secondary antibody would be produced in another host (e.g., swine or sheep) and directed against rabbit antibodies. Fused cells are grown on medium which selects for hybrid growth, but repeated cloning is performed to verify only one cell fusion type is present. Applications of immunofluorescence methods in aquatic systems include marine bacteria, cyanobacteria, eukaryotic ultraplankton, and freshwater systems. Furthermore, for photosynthetic picoplankton, which are also recognized by their characteristic autofluorescence, the diversity within a group of organisms in the field can be investigated.
