Dear Sir. Concerning your issue about the efficient way to extract DNA From Microcystis aeruginosa species. Two different filter types for the cell harvest of Microcystis sp. that were either freeze-dried or stored frozen, and two different methods for DNA extraction were compared. DNA extraction was achieved by standard phenol-chloroform extraction or by a faster commercially available purification kit (DNeasy ®, Quiagen). In general there was good agreement between the cell number equivalents of phycocyanin (PC) genotypes that were estimated using the Taq nuclease assay (TNA) between both filter types and the storing of samples. The standard DNA extraction procedure gave higher numbers of PC genotypes when compared to the DNeasy procedure. I think the following below links may help you in your analysis: