Isolation of queuine from bovine amniotic fluid.

A facile method for isolation of large quantities of queuine from bovine amniotic fluid is described. Queuine was sequentially purified by cation-exchange chromatography, adsorption chromatography on Sephadex G-25, and size-exclusion chromatography on Sephadex G-10. The queuine isolate was identified by its participation in the queuine-guanine tRNA transglycosylase reaction and comparisons with authentic queuine.