Serological techniques

To ensure the safety of food products, representative samples must be inspected so that foodborne bacteria can be identified.15,18,19 Bacteria producing heat-stable enterotoxins, such as Staphylococcus aureus, may be identified by biochemical and serological techniques.20,21 Molecular methods are now widely used for the identification of many pathogenic foodborne bacteria,15,22,23 In addition bacteria used as starter cultures for cheese, yogurt, other fermented foods and beverages, and probiotic dietary supplements may be identified for quality assurance.22,24,25... 

Serological techniques can detect target bacteria rapidly in mixtures, but their accuracy depends on the specificity of the antibody used. The use of monoclonal instead of polyclonal antibodies may increase specificity.49,52,58 However, because the same epitope can be present in more than one species, a monoclonal antibody against one species may cross-react with other bacteria.50 For this reason serological methods are not always successful for detection of bacteria in environmental samples and nucleic acid-based methods are now commonly used. 

Serological techniques, such as latex agglutination and micro-precipitation, which were used for routine virus indexing in... 

The HLA-DP specificities are detected not by serological techniques but by a cellular method known as the primed lymphocyte typing (PLT) test (SIO, Wl). More recently, these specificities have been detected by Southern blotting with appropriate probes and restriction enzymes, and by using monoclonal antibodies in an ELISA (B15). Six HLA-DP specificities are currently recognized (Table 1). 

Additional serological techniques, such as complement consumption tests, radioimmunoprecipitation (Gleich and Stankievic 1969), fluorescence polarization (Dandliker et al. 1965), and variations of sandwich hemagglutination techniques (e.g., red-cell-linked antigen-antiglobulin reaction Kraft et al. 1976), have been used in the detection of antipenicillin antibodies, but all appear to have been supplanted by modern RIA and ELISA techniques. 

In recent years, serological techniques have been developed for identifying and enumerating wild yeasts in the presence of culture yeast (see Chapter 16) [92, 93]. It is now possible by fluorescent antisera to detect under an ultraviolet microscope certain wild yeasts (including those in the genus Saccharomyces) at levels as low as one cell per 10 culture yeasts. 

Molecular techniques are now being used increasingly in the study of viral infections. They are especially useful either as a supplement to existing serological techniques or as an alternative when such techniques do not exist. 

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