5,6dmb is used for vitamin B12 production, i am using it for vitamin B12 production from microbes, i need to prepare 5,6dmb stock solution to be added in production media.
It depend on how strong you need your stock solution and how far this stock will be diluted in the final medium. for example a solution in ethanol can get as high as 50 g/l. A slightly acidic water solution might be better if no additional organics are preferable.