Abstract: Conventional RNA extraction methods have been shown to produce poor-quality RNA when applied to Cycas revoluta because of abundant secondary metabolites included. With modification of the standard cetyltrimethylammonium bromide (CTAB) method by adding borax (disodium tetraborate decahydrate ) andβ-mercaptoethanol to eliminate the interference of polyphenol and polysaccharides , an effective protocol was developed . This modified protocol could extract high quantities of RNA from cycad leaves at about 930μg per gram of fresh weight . Both A260􊄯230 and A260􊄯280 ratios were around 2, indicating that RNA is of high quality. The RNA quality was confirmed by Northern blotting analysis and reverse transcription polymerase chain reaction (RT-PCR). The modified protocol could be successfully extended to other plants containing secondary metabolites .

Key words: Cycas revoluta