Apparatus for retrieving liquid samples from test tubes

摘要

Apparatus is disclosed for mixing and then withdrawing a sample of a liquid suspension from a multiplicity of upright vials for subsequent processing of the sample in individual batches. A holder supports the vials in a row and advances them in incremental steps so as to present them at an aspiration station. An aspirator at the station includes a downwardly open suction tube that can be vertically inserted into and withdrawn from the vial. While in the vial, the tube is subjected to a vacuum to withdraw the sample from the vial for flowing it to an instrument. The suction tube is surrounded by a rotary mixer which is activated prior to the withdrawal of the sample to uniformly disperse particles in the liquid. The suction tube and the mixer are generally horizontally movable so that they can be inserted in a container holding a rinsing solution after each withdrawal of a sample liquid from a vial to prevent cross-contamination of the samples. The rinsing solution in the container is drawn into the suction tube and used for purging the previous sample from all conduits.