Abstract: A method and apparatus for handling samples such as blood samples for hemostasis. The sample is transferred from a test tube into a cuvette which has been released from a supply of cuvettes. Prior to transferring the sample, a needle is introduced into the sample and automatically senses the level or height of the sample in the test tube. The presence of vials of reagent is optically confirmed. Reagents are to be delivered through a delivery tube into the cuvette and the delivery tubes are initially primed with reagent. The presence and orientation of the cuvette are verified and the sample transferred into the cuvette, the reagent automatically delivered into the cuvette, and the reaction such as, but not limited to, blot clotting occurs in the cuvette. The occurrence of the reaction is optically confirmed. The system and method controls the sequential release of stacked cuvettes in addition to confirming the presence and proper orientation of the cuvettes.