Direct recovery and molecular analysis of DNA and RNA from soil.

A simple method for the recovery of DNA and direct detection of nif and Tn5 sequences in soil has recently been presented by Selenska and Klingmüller. On the basis of that method we have developed a procedure for the recovery and separation of DNA and RNA from the same soil sample. A 550 bp sequence from the Kmr gene of Tn5 was identified by PCR amplifications in total DNA and RNA, isolated from soil inoculated with a nitrogen-fixing Enterobacter agglomerans 19-1-1, which carries this transposon. Hence, not only the presence of the Kmr gene of Tn5 but also its expression (mRNA synthesis) in the analyzed environmental samples was detected. The authenticity of the products of PCR amplifications of DNA and mRNA was confirmed by the PhotoGene hybridization technique.