Cylindrospermopsin is provided as a lyophilized powder in an amber vial, at the specified mass purchased and shown on the vial. It should be easy dissolved in water or methanol or ethanol, with repeated rinsing of the sides of the vial with a pipet tip to fully dissolve the product. Once dissolved in one of these recommended solvents, the product is stable for ≥1 year when stored at -20oC. For biological applications, dissolved toxin should be diluted in an appropriate buffer for the application, reducing the organic solvent content to a level that it will not impact the application. For HPLC or other chemical applications, it should be diluted in an appropriate solvent or mobile phase.