SIGNAL SYSTEM AND ELEMENTS USED THEREIN

摘要

A method for measuring intracellular ATP and/or gene expression, which metho d comprises transforming a cell with a construct which encodes a luciferase an d a luciferin recycling protein, introducing luciferin into said cell, and monitoring biolominescent signals from said cell. Novel luciferin recycling proteins are also described and these, together with their use in the production of optically active enzyme substrates are claimed.