A rapid and sensitive fluorimetric assay for adenosine, inosine, and hypoxanthine.

A rapid and sensitive fluorimetric assay for inosine and adenosine is described in which either or both metabolites are enzymically converted to hypoxanthine, which is then estimated by the rate of appearance of hydrogen peroxide after the addition of xanthine oxidase. The method has been used to assay solutions over the range 0.2 to 30 μmol/liter although this is not the ultimate sensitivity possible. Uranyl acetate as protein precipitant gave good recovery of inosine and adenosine from blood and was compatible with the assay.