The best way of taking aliquots of liquid from large supply bottles is by using bottle-top dispensers. The requirements of such a bottle-top dispenser are clear: it must be capable of exact reproducible dispensing that does not waste any reagent. When dealing with aggressive liquids, such as solvents, it must ensure the best possible protection for the users and their laboratory. This safety is guaranteed by the Eppendorf Varispenser^®. It is, of course, autoclavable and extremely chemical-resistant.