A novel, simplified technique for preservation and rapid isolation of total RNA from the toxic dinoflagellate Alexandrium catenella (Dinophyceae)

A simple and rapid protocol for isolating high-quality RNA from the neurotoxic dinoflagellate Alexandrium catenella is described. We compare the use of fresh cells, preserved cells and different treatments of cell homogenisation on RNA yield and quality. Alexandrium catenella is an ideal model species for difficult-to-lyse microalgae because of its tough cellulose cell wall. Immersing cells immediately in RNAlater (Ambion) enabled long-term preservation of cellular RNA that would otherwise degrade rapidly. This solution is easy to use and nontoxic, and can be taken in the field. Grinding preserved cells in a microfuge micropestle could be performed with or without liquid nitrogen and was the most reliable method of homogenising the sample without shearing or degrading RNA. RNA was purified using the Qiagen column-based RNeasy Plant Mini Kit. DNase treated and successfully used for cDNA synthesis for reverse trancriptase-polymerase chain reaction, indicating its usefulness for studying functional genomies of harmful dinoflagellates and other microalgae.