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Kinetic analysis and modeling of firefly luciferase as a quantitative reporter gene in live mammalian cells
Author(s) -
Ignowski Jolene M.,
Schaffer David V.
Publication year - 2004
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20059
Subject(s) - luciferase , intracellular , context (archaeology) , reporter gene , gene expression , biology , chemistry , cell culture , microbiology and biotechnology , gene , transfection , biochemistry , genetics , paleontology
Abstract Firefly luciferase has proven to be a highly sensitive and quantitative reporter gene for studying gene delivery and regulation, and its recent use in live cells and organisms promises to further expand its utility. However, the intracellular behavior and properties of the enzyme are not well characterized. Specifically, information on the intracellular kinetics and stability of luciferase activity is necessary for real‐time luminescence counts from live cells to be quantitatively meaningful. Here, we report a dynamic analysis of luciferase activity in the context of living mammalian cells. We have determined the relative light units measured in living cells to be proportional to that found in cell lysate. We have also calculated the K m of luciferase in living cells to be ≈ 1 m M , a value much higher than the 10 μ M found for pure enzyme in vitro. In addition, a 2‐hour half‐life of luciferase activity in live cells was measured in real time. Finally, we have modeled luciferase activity in live cells for the purposes of understanding and translating the luciferase signal into a more effective metric of gene expression and cell behavior. © 2004 Wiley Periodicals, Inc.