Thermo Scientific 5-Fluoroorotic Acid (5-fluorouracil-6-carboxylic acid monohydrate; 5-FOA) is used in yeast molecular genetics to detect expression of the URA3 gene, which encodes orotine-5'-monophosphate (OMP) dicarboxylase. Yeasts with an active URA3 gene (Ura+) convert 5-FOA to fluorodeoxyuridine, which is toxic to cells (see the scheme below). Yeast strains carrying a mutation in the URA3 gene grow in the presence of 5-FOA if the media is supplemented with uracil. 5-FOA is frequently used in experiments with Saccharomyces cerevisiae (URA3), Schizosaccharomyces pombe (URA4 and URA5), Candida albicans (URA3), and E. coli (pyrF).

Applications

• Detection of URA3 gene expression in yeast
• Construction of yeast 2-hybrid libraries
• Other areas of yeast genetics including gene replacement, analysis of transposable genetic elements, and identification of gene mutation

Note
• Low solubility in water
• Solubility in dimethylsulfoxide is greater than 150 mg/mL
• Preparation of a 100 mg/mL solution in dimethylsulfoxide is recommended