摘要 |
Assays, preferably high throughput assays, for determining cysteine concentration, cysteine synthase activity, and identifying herbicides, fungicides, bactericides, and insecticides. Cysteine concentration is quantitated by contacting cysteine with a coumarin dye capable of conjugating with cysteine but not to O-acetyl serine or sulfide; exciting the conjugate with UV light; and detecting fluorescent light emitted by the conjugate. Cysteine synthase activity is determined by combining O-acetyl-L-serine, sulfide and cysteine synthase to form a reaction mixture under conditions suitable for cysteine production; contacting the reaction mixture with an appropriate coumarin dye; subjecting the reaction mixture to UV light; and detecting fluorescent light emission.
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