Phenotypic Detection Methods

Conventional methods for the detection of PTSAg-producing S. aureus strains are based on biological or immunological procedures detecting or measuring the toxin in culture supernatants of suspected S. aureus strains in contaminated food extracts or in patient specimens.

Biological methods using animals and human volunteers were the first approaches to determine the production of SEs. Monkeys have been considered to be the primary animal model to study the emetic activity of SEs. Investigating the emetic activity in biological assays is the most important basis to characterize a candidate exotoxin as yet unknown SE.

Since antigen-antibody reactions became available, the adaptation of immunodiffusion assays (e.g., Ouchterlony technique) for detection of toxin proteins have radically changed the diagnostics of PTSAgs. Further increase of sensitivity by about 100-fold because of the introduction of reversed passive latex agglutination, radioimmunoassay (RIA), and enzyme immunoassay (EIA) methods made it possible to detect as little as 1 ng/mL of toxin. Because biological assays are less specific and sensitive and restricted by high costs, availability of the experimental animals, and ethical considerations, immunological

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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