Total RNA was isolated from two months old wheat, rice, tobacco and sweet potato. The procedure used was simple and provided pure RNA preparation. Lysis of plant tissue in a buffer with guanidine thiocyanate and CsCl density gradient centrifugation separated RNA from the rest of the cellular components. Subsequent cholroform/1-butanol extraction and ethanol precipitation were necessary to ensure contaminant-free RNA preparation. Storage of the lysed plant tissue in the buffer with guanidine thiocyanate preserved the sample for two months without noticeable RNA degradation.