Bioassay systems Biological activities

Bioassays represent the most relevant potency-determining assay, as they directly assess the biological activity of the biopharmaceutical. Bioassay involves applying a known quantity of the substance to be assayed to a biological system that responds in some way to this applied stimulus. The response is measured quantitatively, allowing an activity value to be assigned to the substance being assayed. 

Concentration techniques, applied to assign priority pollutants, function as an interface between the environment, chemical analysis, and bioassays. The transition of harmful pollutants in an environmental system to multicomponent concentrates derived from that system is the principal challenge of concentration techniques aimed at the assignment of organic priority pollutants. A compatible combination of chemical and biological methods must be used. These methods can vary from the development of analytical procedures based on the observed biological activity of fractions of an environmental concentrate to the toxicological... 

A bioassay is an analytical procedure that uses a responsive biological system (biological function) to measure the biological potency of a product (Mire-Sluis et al., 1996). The most appropriate method to determine it is by comparing the biological activity of a sample with a well-characterized reference standard. 

The evagination of imaginal discs of Dipteran and Lepidopteran insects is a well-characterised ecdysteroid-dependent system, which has been used by several authors to develop bioassays [183-187], However, they have been used to only a limited extent to compare the biological activities of ecdysteroids (Table 3 ). 

Traditionally, TSH activity was determined by bioassays. There is now sufficient evidence for the correlation of biological activity and results of immunoassays. Reference standards are available for rat TSH, dog TSH and human TSH (DSL Diagnostic Systems 2005). Immunometric measurements of TSH are available (Utiger 1979, Spencer 1994, Meinhold et al. 1994), for rat radio-immunoassay methods see section I.0.4.3 of this Chapter. Large scale synthesis of recombinant human thyrotropin has been reported (Cole et al. 1993, Hussain et al. 1996). The role of... 

Moreover, the observation of an interesting antibiotic activity for some Lactarius extracts (3) stimulated the search of new biologically active compounds among those isolated from these mushrooms. In fact, simple bioassays (4) led to the identification of new products with antimicrobial, cytotoxic, antifeedant and other interesting activities. No less important was the observation that some species seem to withstand attack from parasites such as snails and insects better than others. In fact, it has been shown that resistant species are armed with a chemical defence system which protects the mushrooms from predators and invaders. 

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