This protocol describes how to prepare a 100x BG-11 +N stock.1x BG-11 media could be created from the stock and supplemental stocks and trace metals could be added afterwards.This protocol is based on Anne Behle M.Sc. Reciepe for standard BG-11 media protocol.Recipes for standard and alternative BG11 for culturing freshwater cyanobacteria, such as Synechocystis sp. PCC 6803, as described.Media is usually not suitable for marine cyanobacteria.