A monophasic solution for isolation of RNA devoid of polymerase chain reaction-detectable genomic DNA contamination

Commercially available reagents and published protocols are widely used for RNA isolation. However, genomic DNA contamination in isolated RNA is a potential problem. Here we describe a simple, inexpensive method for eliminating genomic DNA contamination beyond the level of PCR-based detection through reduction of the guanidine thiocyanate concentration (1.5M) in a single monophasic solution based on Chomczynski-Sacchi reagents. The new method can be used to isolate small and large RNA species of high quality and can be completed within an hour.