Advantages of Fluorescence Fluorescent, chemiluminescent, and colorimetric approaches have been used as alternatives to radioactive detection methods. Fluorescence detection methods offer the advantages of high sensitivity, easy quantitation, stability, and low cost. In addition to allowing quantitative comparisons, linear accumulation of product increases the sensitivity of the fluorescent assay because low enzyme activity can be detected with longer incubation times. In contrast, the kinetics of chemiluminescence reach a steady-state plateau after 30 to 90 minutes. Both FDG and its fluorescent products are reasonably stable when stored in TAE at 4 C in the dark.
Reagent stability allows plates to be saved and scanned together when convenient.
In contrast, chemiluminescent assays must be evaluated soon after the assay is terminated. Finally, fluorogenic substrates are less expensive than their chemiluminescent counterparts. FDG is more than 100 times less expensive per assay than chemiluminescent substrates for b -galactosidase. Discussion b -Galactosidase is a useful marker enzyme for many standard molecular biology procedures. The enzyme is both easy to detect and limited in its endogenous expression in mammalian cells, making it ideal for monitoring the success of transfection experiments.