An improved method of detecting DNA-RNA hybrids bound to nitrocellulose filters

The enzymic removal of DNA-RNA hybrids from nitrocellulose filters before counting results in an increase in the detectable counts per minute and a decrease in the variability between duplicate samples. This permits the use of filters containing smaller amounts of DNA, and the use of RNA which has a lower specific activity, without losing statistical accuracy. Both accuracy and precision in the determination of specific activities of RNA samples are increased by digesting the RNA prior to counting.