Rapid screening of radioprotective drugs in vivo

The traditional test for radioprotection, a measurement of the LD₅₀/₃₀, requires a 1-mo wait between treatment and result. An alternative method is proposed which requires only a 3-day wait. It requires fewer mice but more man-hours than LD₅₀/₃₀ measurement. The frequency of micronuclei which result from chromosomal aberrations is the criterion of damage. It is shown that a thiophosphate compound S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR 2721) produced a similar protection measured in this way as had been found by the traditional method.