Improved protocol for isolation of high-quality total RNA from different organs of Phaseolus vulgaris L.

A modified protocol was developed to obtain high-quality total RNA from various mature organs, including leaves, seeds, pods and testae, from different cultivars of Phaseolus vulgaris L. grown under optimal conditions or subjected to severe drought; stress conditions leading to the accumulation of numerous secondary metabolites can affect RNA quality. This modified procedure is based on CTAB extraction protocols. Modifications in this protocol prevent oxidation of phenolic complexes, the precipitation of proteins, DNA and degradation of RNA; also, it is effective at removing secondary metabolites. The RNA obtained following this procedure showed high quality as revealed by a high RNA integrity number and high 260/280 nm (>2) ratio, the requirements needed to increase reliability of diverse molecular analyses.