Abstract: A dispenser which can deliver precise small amounts of a liquid is disclosed. The dispenser is particularly suited to applying reagents in a biological test such as an immunoassay. It includes a reservoir chamber linked to a dispense chamber via a check valve, the two chambers preferably being in the form of syringes. An outlet line leading from the dispense chamber to a nozzle includes a delay check valve (preferably a ball inside a cylindrical chamber) which allows continuous outward flow, but shuts off flow in the reverse direction after allowing a predetermined volume to pass. The process of refilling the dispense chamber from the reservoir chamber creates reverse flow in the nozzle and causes a hanging drop of liquid at the tip of the nozzle to be withdrawn.

Abstract: A snap cap apparatus is provided for sealing individual or a plurality of containers having necked openings. The snap cap apparatus comprises one or more caps, each cap having a pliable cover, the cover supporting one or a plurality of caps for sealing corresponding containers having necked openings. The snap caps providing a chamber and concentrically positioned within the chamber are stopper elements with a base connected to the thin pliable cover. The stopper elements terminating in an exposed end portion which is tapered to a smaller dimension than the base, the exposed end portion being positioned proximal to the open end of the chamber of the cap, the cap and stopper element combining to define an open ring portion for receiving container opening neck portions.