Nitrocellulose filter binding has been used to measure the association of proteins to both DNA and RNA for many years. Yarus and Berg (1 ) first described the application of the method for characterization of aminoacyl-tRNA synthetase:tRNA association; other RNA applications include the R17 coat protein:RNA hairpin interaction (2 ), ribosomal protein:RNA binding (3 ), and TFIIIA:5S (4 ). The method has also been extensively applied to DNA:protein systems.
