Abstract: The invention relates to a pump of the type including a moving member mounted to move relative to a support, the moving member having a central duct in which substance to be dispensed penetrates via at least one opening, the support co-operating with the moving member to define, around said central duct, a pump chamber of variable volume, said pump also having a membrane with a central portion in the form of a sleeve that is open at its top end and closed at its bottom end, said central duct being inserted in said central portion, the membrane being organized to isolate the pump chamber from the opening(s) of said central duct while the volume of the pump chamber is increasing and substance is being sucked into it. At least one of the membrane and the central duct is shaped to prevent a leakproof annular zone forming between the membrane and the central duct which would prevent the substance contained in the pump chamber from flowing via said central duct while the volume of the pump chamber is decreasing.

Abstract: A method and apparatus for an automated biological reaction system is provided. In the processing of a biological reaction system, there is a need for consistently placing an amount of fluid on a slide. In order to accomplish this, several methods are used including a consistency pulse and a volume adjust means. Moreover, in order to reliably operate an automated biological reaction system, the dispenser must be reliable, easy to assemble and accurate. Among other things, in order to accomplish this, the dispense chamber is substantially in line with the reservoir chamber, the reservoir chamber piston is removed, and the flow of fluid through the dispenser is simplified. Further, in order to operate the automated biological reaction system more reliably, the system is designed in modular pieces with higher functions performed by a host device and the execution of the staining operations performed by remote devices.