Cre stoplight: a red/green fluorescent reporter of Cre recombinase expression in living cells.
The Cre/lox system is a powerful genetic tool with which to manipulate the genome. Here, we describe the development of a simple reporter system for Cre recombinase, called the Cre Stoplight. In the absence of Cre, the red fluorescent protein is expressed; when Cre catalyzes a recombination event, the green fluorescent protein is produced. Testing this system in transiently transfected cells showed that it produced robust signals (90% of the cells converted from red to green) when equal amounts of the plasmids encoding Cre recombinase and the Cre Stoplight were used. A 1:100 ratio of enzyme to reporter plasmid produced similar results, and a 1:10000 ratio was necessary to significantly reduce the number of cells converting to green (1%).
Yang
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Yale University School of Medicine, New Haven, CT 06520, USA.
Hughes
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D002460:Cell Line; D049452:Green Fluorescent Proteins; D006801:Humans; D019426:Integrases / Q000502:physiology*; D008164:Luminescent Proteins / Q000378:metabolism*; D011995:Recombination, Genetic; D014162:Transfection; D014764:Viral Proteins / Q000502:physiology*
D008164:Luminescent Proteins; D014764:Viral Proteins; C413663:fluorescent protein 583; D049452:Green Fluorescent Proteins; C045073:Cre recombinase; D019426:Integrases