Isolation of high molecular weight plant nuclear DNA suitable for use in recombinant DNA technology.

: Nuclei isolated from leaf cells of broad bean (Vicia faba L) by a newly developed method based on the use of citric acid in the isolation medium and flotation on a Percoll cushion yielded high molecular weight plant nuclear DNA which was suitable for (i) analysis by restriction endonucleases, (ii) molecular cloning and (iii) genomic blot hybridization. Starting from nuclear preparations obtained by this method, U2 small nuclear RNA-specific DNA sequences were detected in Vicia faba L. This is the first report on the demonstration of small nuclear RNA-specific DNA sequences in plant material.