Optimised protocols for RNA extraction from a broad taxonomic range of algae

Despite advancements in RNA extraction methods, RNA extraction from sources rich in polyphenols and polysaccharides such as algae and seagrasses remains a challenge. Here we present a RNA extraction strategy using a hexadecyltrimethylammonium bromide (CTAB) extraction buffer and demonstrate its effectiveness on a broad range of red, green, and brown algae, as well as on the cyanobacterium Arthrospira platensis and the seagrass Zostera marina . For the vast majority of tested samples we achieved high yields of RNA comparable to those obtained from higher plants by commercially available kits (ranging from 3.9 to 125.9 µg RNA g −1 fresh weight). Analysis by UV/Vis spectrometry and capillary electrophoresis revealed high purity and integrity of obtained RNA extracts. For highly challenging species of brown algae like Fucus vesiculosus , Fucus serratus and Dictyosiphon foeniculaceus , we established an alternative procedure using a sodium dodecyl sulfate (SDS) extraction buffer in combination with a commercial kit. With this protocol, even higher RNA yields up to 317.0 µg g −1 fresh weight were extracted from polysaccharide-rich brown algae tissues. This study can serve as a guideline and starting point for the development of RNA extraction protocols for so far unstudied algal species from very diverse taxa.