An improved method for efficient isolation and purification of genomic DNA from filamentous cyanobacteria belonging to genera Anabaena, Nodularia and Nostoc

The aim of this work was to develop an improved method for isolation and purification of genomic DNA from filamentous cyanobacteria. The method described here employs a modified phenol extraction-based procedure. It allowed us to obtain a high yield (60–620 μg/g wet weight, depending on the cyanobacterial strain) of pure and undegraded genomic DNA (A260/A280 ratio of about 1.8 and A260/A230 ratio of about 2.0). Genomic DNA, isolated from cyanobacteria belonging to the genera Anabaena, Nodularia and Nostoc has been successfully used for construction of gene libraries. Thus, this method can be used in procedures requiring highly purified cyanobacterial DNA.