In the ultimate design of such lines of fish, we may wish to engineer a biomonitoring system with varying responsiveness, so that the detection limits can be tailored to specific needs. A system that responds to concentrations of contamination well below the levels of biological relevance is no more useful than a system that is too unresponsive. Cartoon of our proposed transgenic fish sentinel for biological monitoring. Fish are then incubated with luciferin, which is rapidly taken up into the tissues of the fish. Luciferin is then oxidized by luciferase, and light is produced.
Light production is quantitated in a luminometer.
This assay does not require killing the fish and allows for repeated analysis of the same site with the same fish. The sensitivity of the system can be manipulated by varying the sequence of the response element.