Fingerprinting Double‐Stranded Non‐Radioactive RNA from a Fungal Virus

The fingerprinting technique has been applied to double‐stranded viral RNA. Under appropriate conditions pancreatic and T 1 ribonuclease digests were obtained which upon two‐dimensional paper electrophoresis yielded specific patterns, similar to those obtained from single‐stranded RNAs. The structure of some simpler nucleotides on the fingerprints have been determined. The method seems suitable to characterize and sequence all kinds of double‐stranded RNA molecules. Labelling of the virus in vivo yielded RNA preparations of rather low radioactivity. Polynucleotide kinase was used therefore to label the digest of non‐radioactive RNA for fingerprinting. The possibilities and limitations of this technique for sequencing non‐radioactive nucleic acids is discussed.