Differentiation of DNA and RNA on filter paper discs

Differentiation of radioactive DNA and RNA deposited on filter paper discs can be accomplished by a relatively simple procedure. RNA can be efficiently removed by incubating the dises, impaled on pins, with 0.2 ml of 0.5 n NaOH for 90 min at 37°C. DNA can be removed after NaOH hydrolysis by treating the discs with 5% TCA for 30 min at 90°C. A correction is necessary to determine the actual amounts of DNA and RNA in order to account for the loss of DNA (13.8%) during the NaOH hydrolysis procedure.