Biological assessment activity assays

The manufacture of biological products, unlike that of pharmaceuticals, uses materials that present variability. The active substance is generally produced in small quantities and needs to be separated from complex mixtures containing several types of contaminants. Lots are generally small and quality control tests are usually based on biological techniques that present higher variability than physicochemical assays. The processes are also susceptible to microbial contamination. The in-process controls are of fundamental importance to detect quality deviations that cannot be assessed through assays performed only on the final products. 

As for any new lot of material, assessments of biological activity should be performed to demonstrate the efficacy of the product. This may be achieved though the use of animal-based biological assays, cell-based assays that evaluate the material at the cellular level, and biochemical activity assays such as enzymatic action. Standards should be properly defined. Potency and efficacy for individual lots of material can therefore be defined. 

The biological activity of the compounds was assessed in two binding assays using [ H]-CP 55,940 (see Table 6.36) and [ H]-rimonabant (data not shown), and their functional activity determined using a GTPyS assay. Upon... 

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. 

The assay microorganisms in Polytox are a blend of bacterial strains originally isolated from wastewater [48]. The Polytox kit (Microbiotest Inc., Nazareth, Belgium), specifically designed to assess the effect of toxic chemicals on biological waste treatment, is based on the reduction of respiratory activity of rehydrated cultures in the presence of toxicants. The commercially available kit is specihcally designed for testing wastewaters. Quantative results can be obtained in just 30 minutes. 

Glavind and Holmer proposed a method of determination of antioxidants by TLC using the DPPH radical. They sprinkled a plate with separated substances with methanol solutionofthe radical and observed discoloration where substances able to quench radicals were present [57]. The TLC-DPPH assay allows a researcher to access the analysed substances and to assess the biological activity of individual compounds. Another advantage of the method is the possibili-... 

Two recombinant allergens from olive pollen (Ole e 3 and Ole e 8) were produced in Arabidopsis and their relative biological activities assessed to be positive via calcium-binding assays. The immunological behavior of these recombinant allergens was equivalent to natural allergens, as demonstrated by their ability to bind to allergen-specific rabbit IgG antiserum and IgE from sensitized patients (Ledesma et al., 2006). 

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