Total RNA Extraction for the Red Seaweed Gracilaria changii ( Gracilariales , Rhodophyta )

Five different RNA extraction methods have been tried out on the red seaweed, Gracilaria changii collected from the mangrove area at Morib, Selangor, Malaysia. Two methods, one utilising guanidinium thiocyanate, and another using cetyltrimethyl ammonium bromide (CTAB), were found to be potential alternatives to obtain pure RNA. By incorporating sand while grinding the tissue, the method using CTAB was found most suitable to obtain pure RNA (high A260:280nm ratio) with high yield (0.16μg RNA per gram of fresh tissue). Introduction The Rhodophyceae and Phaeophyceae are important producers of phycocolloids, e.g. agar, agarose, algin and carrageenan (Hoppe & Schmid 1969). These polysaccharides, credited for their gel-forming capability, are widely used as immobilising and encapsulating agents for analytical elements, especially in the emerging enzyme and biosensor technology in medical fields (Jensen 1993; Renn 1997). Gracilaria (Gracilariales, Rhodophyta), with its agar content ranging from 4.4% to 40.0%, is the