Large scale production of transfer ribonucleic acids from E. coli K-12 MO7

An engineering-scale procedure for the recovery of 300–400 g batches of mixed transfer ribonucleic acids is described. Semicontinuous growth of E. coli K-12 MO7 yielded 77 kg of harvested cells in four days. Phenol extraction and ethanol precipitation recovered a crude tRNA material that was further purified by DKAE-cellulose chromatography in runs of 1 × 10⁶ A₂₆₀ units each on a 6 × 30 in. column using a 240 1, gradient elution. The purified tRNAs were partially concentrated and resolved into three groups.