Extraction of RAPD-friendly DNA from Laminaria japonica (Phaeophyta) after enzymatic dissociation of the frozen sporophyte tissues

A new extraction protocol has been developed to obtain high quality DNAfrom Laminaria japonica, which involves enzymatic dissociation ofsporophyte tissues and subsequent elimination of the remainingpolysaccharides with cetyltrimethyl ammonium bromide. Unicells isolatedfrom frozen kelp tissues with alginate lyase prepared from the abalone Haliotis diversicolor were used to extract total DNA; the yield wasapproximately 13 to 22.5 g DNA g^-1 (wet sporophyteweight). The average size of genomic DNA was around 23 kb estimated byagarose gel electrophoresis, and the purity of total DNA determinedspectrophotometrically as the ratio of OD₂₆₀/OD₂₈₀ wasabout 1.7. The extracted kelp DNA (20–40 ng) could be usedsuccessfully as a template for polymerase chain reaction (PCR) under theoptimized conditions (100 M dNTP, 0.2 M primer, 1.0unit Taq DNA polymerase). The random amplified polymorphicDNA (RAPD) patterns were highly reproducible. These results suggest thatthe contamination by soluble polysaccharides which interferes with RAPDreproducibility was largely controlled. This RAPD-suited method for DNAextraction from kelp sporophytes using enzyme treatment providedsufficient material, and was inexpensive and convenient to carry out.