Efficiency of RNA extraction methods from coneflower medicinal plant

Coneflower is a valuable medicinal plant containing high levels of secondary metabolites, but no suitable method for extraction of the entire RNA has been introduced yet. In present study, four methods of RNA extraction including lithium chloride, RNAX-Plus kit, phenol/SDS and lithium chloride/phenol were investigated. For confirming the quality and purity of RNA, spectrophotometer and agarose gel electrophoresis of 1.5% were used. The high absorption ratio of RNA solution at a wavelength of 260 nM to 280 and 230 nM, observation of ribosomal RNAs and the lack of smear on the gel were considered as criteria for determining samples quality. The highest and the lowest qualities of RNA contained 2.9 μg/100 mg of fresh leaves by phenol/SDS method and 1/2 μg/100 mg of fresh leaves by lithium chloride/phenol method, respectively. Therefore, phenol/SDS method is introducing as the most suitable method for RNA extraction from coneflower.