An improved method for isolating RNA from dehydrated and nondehydrated chili pepper (Capsicum annuum L.) plant tissues

High-quality RNA is important in studying gene expression. This report describes an improved method for isolating intact purified RNA from dehydrated organs of chili pepper plants. Common RNA extraction protocols have produced poor yields because dehydrated leaves accumulate polysaccharides and RNases. Our protocol is based on a guanidine thiocyanate extraction combined with additional purification steps using butanol and the ionic detergent CTAB (cetyltrimethylammonium bromide). Using this protocol, RNA yields ranged from 40-70 mug of total RNA per 200 mg of fresh tissue. This method can be adapted to large-scale isolations, allowing the recovery of larger amounts of intact RNA (up to 250 mug per gram of fresh tissue).