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Luminescence analysisThe firefly luciferin-luciferase system is the most frequently used bioluminescent reaction for analytical purposes. It can be used for assays of ATP and any enzyme or metabolite participating in ATP forming or degrading reactions (cf. ATP monitoring). ATP can be used as a measure of biomass (amount of living material), since the intracellular level of ATP is similar in all living cells, and is rapidly degraded when the cell dies. Rapid microbiology and hygiene monitoring are popular applications of the ATP assay. The gene coding for firefly luciferase has become one of the most frequently used reporter genes used in molecular biology to study transfer and expression of genes. Bacterial luciferase combined with oxidoreductase enzymes can be used to monitor NADH and NADPH in a similar way, as is done with firefly luciferase for ATP. Horseradish peroxidase and luminol can be used to measure H2O2 production. Several enzymes and other substances participating in luminescent reactions may be used as labels in immunoassays. Thus luminescence analysis has many applications in a variety of areas. If, e.g., a completely new system for clinical analysis should be built up today, a likely candidate for the analytical system would be luminometry. This would enable all assays (assays of enzymes and metabolites, immunoassays and many bacteriological assays) to be performed using the same instrument. The assay principle
The Kits are based upon the bioluminescent measurement of ATP which is present in all metabolically active cells. The bioluminescent method utilises an enzyme, luciferase, which catalyses the formation of light from ATP and luciferin according to the following reaction. The emitted light intensity is linearly related to the ATP concentration and is measured using a luminometer. Bioluminescence is now the most widely used method for the assay of ATP due to its very high sensitivity, wide dynamic range and ease of use. |