Effects of preservation and storage of microcrustaceans in RNAlater on RNA and DNA degradation

Elena Gorokhova

Limnol. Oceanogr. Methods 3:143-148 (2005) | DOI: 10.4319/lom.2005.3.143

ABSTRACT: Methods of preserving nucleic acids are increasingly in demand because of the recent advances in molecular and biochemical approaches to ecology. The RNA storage reagent RNAlater® was tested as an alternative method to deep-freezing for preserving RNA and DNA in zooplankton. Artemia spp. nauplii were used as test organisms. Individual RNA and DNA contents were monitored over a time period of 8 months to evaluate the effects of preservation and storage. Treatments included (1) freezing at –80°C, (2) preservation with RNAlater, followed by storage at 5°C, and (3) preservation with RNAlater and storage at room temperature. Freezing at –80°C was the only treatment that did not result in significant change from the initial values in any of the nucleic acids, nor at any time of the experiment. At 5°C, significant RNA degradation was not observed until 8 months after preservation while no significant changes in DNA were detected. In samples stored in RNAlater without refrigeration, RNA did not exhibit significant decrease for at least 1 month, and DNA for at least 2 months. As RNA and DNA degraded at roughly the same rate, this resulted in little or no changes in RNA:DNA ratios, but withintreatment variability increased strongly. Thus, RNAlater successfully preserved both RNA and DNA for up to 1 month at room temperature, and up to 4 months at 5°C, providing an alternative to the deep freezing. This method will enable a greater integration of molecular methods in ecological studies.