A Rapid and Efficient Method for Isolating High Quality Total RNA from Edible Fungi

A rapid and efficient procedure,the STE(sodium chloride-Tris-HCl-EDTA) method,for isolating high quality total RNA from polysaccharide-rich mycelia of the edible fungi Lentinus edodes,Ganoderma lucidum and a Polyporus sp.is described.The quality of the total RNA isolated by the STE method was superior to that obtained using the Trizol method.The A260/A280 and A260/A230 ratios of RNA isolated by the STE method ranged between 1.80~2.10 and between 1.90～2.30 respectively,whereas the A260/A280 ratio of RNA isolated by the Trizol method was below 1.80,and the A260/A280 ratio was outside the 1.90~2.30 range.Three distinct bands representing 28S,18S and 5S rRNA were observed following electrophoresis of total RNA isolated from the three test strains by the STE method.Electrophoresis of total RNA isolated using the Trizol method resulted in dark bands corresponding to 28S rRNA and 18S rRNA,indicating partial degradation of the RNA.Our data demonstrated that the total RNA isolated by the STE method was of a quality eminently suited for downstream applications.