Abstract: Blood samples are obtained from the tails of animals such as mice or rats by a disposable tube located in a stopper and disposed in a vacuum flask. The tube is of such length that the tail extends into a receptacle at the end of the tube in which the samples are collected. Vacuum is communicated into the interior of the tube via a hole therein and promotes the flow of blood from the tail. The posterior of the animal makes a vacuum tight seal with the top of the tube on which the animal is seated. The tube is disposable after a single use.