
F9001-1 by Zymo Research is 5-Fluoroorotic Acid (5-FOA), 1 g powder, ≥98% purity, MW 174 g/mol. The standard URA3 counter-selection agent for yeast genetics — used in plasmid shuffling, allelic replacement, plasmid curing, and two-hybrid screens in Saccharomyces cerevisiae. Store at −20°C.