The present invention relates to a pressure-tight storage vessel containing a liquid, wherein the storage vessel has an inner floor and an upper side and is closed in a pressure-sealing manner by a closure, and wherein the nature of the storage vessel allows pressure-sealing piercing with at least two hollow needles; and to a method for transferring a liquid from a storage vessel to a reaction vessel, the method comprising the following steps: supplying the storage vessel according to the invention, pressure-sealing piercing with a first hollow needle, which is connected to a rinsing-liquid tank, and pressure-sealing piercing with a second hollow needle, which is connected to the reaction vessel, introducing rinsing liquid from the rinsing-liquid tank, via the first hollow needle, into the storage vessel, the liquid being driven out of the storage vessel, via the second hollow needle, into the reaction vessel; and to an apparatus which is suitable for implementing the method according to the invention.