Abstract: A method of obtaining aliquots or samples from a liquid specimen collection container and an apparatus which automateally perforths those methods involves transferring a sample of liquid from a sealed non-deformingly expandable container containing gas and the liquid without contaminating the liquid remaining inside the container, and comprises (a) non-deformingly volumetrically expanding the sealed container sufficiently to reduce pressure therein below ambient pressure outside the container, (b) applying heat selectively to a locus on said enlarged container to non-invasively create a hole having a diameter effective to equilibrate the pressure inside the container with said ambient pressure without loss of liquid from the container, and (c) non-deformingly volumetrically reducing the container to expel liquid from the container through the hole.