Abstract: A constant-volume increment pipetting arrangement for use particularly in connection with analysis of minute specimen volumes of biological fluids. The arrangement, which is designed to have a very low inertia factor, comprises a pumping unit having a pair of two-port valves with a duct running between a port from each valve, wherein at least a portion of the duct wall is movable to provide a variable volume pipetting chamber. The second port of one valve serves as the intake port for the fluid to be pipetted and the remaining port of the other valve serves as the delivery port. Three reciprocating drive elements are provided, connected one each to the valves and to the movable portion of the duct wall. Associated with the drive elements is a sequential control means, wherein the control means portion for the drive element connected to the moving portion of the duct wall constitutes an electromagnet arrangement energizable by a periodic supply.

Abstract: Apparatus for optically analyzing a solution comprises a tubular enclosure for containing the solution, which enclosure is rigidly mounted on a rotor so that the longitudinal axis of the enclosure extends radially of the axis of rotation. A radially inner end of the enclosure is open and a radially outer end thereof is closed by a transparent wall to constitute two light-transmitting windows through which a light beam is radially directed when the enclosure passes a predetermined place on its path of movement. A light detector is disposable on the axis of the light beam to detect the light beam after passage through the enclosure.

Abstract: A unit for use in optical analysis is adapted to be mounted in a radial position on a centrifuging rotor and comprises a straight tubular cell. One end of the tubular cell is open and the other end is closed by an optically transparent wall which is substantially perpendicular to the longitudinal axis of the cell. The cell receives one component of a solution to be optically analysed and a second component of the solution is received in a recess of a cover of the unit releasably secured in a position closing the open end of the cell. The cover is formed with an aperture connecting the recess of the cover to the cell in the closed position, so that the second component can flow into the cell during centrifuging.

Abstract: An improved device and method for liquid storage and analysis. The device comprises a receptacle defining a U-shaped compartment for a first open-ended branch and a second closed branch. A reaction zone in which the liquid will react with a reagent during analysis is located at the bight interconnecting the branches. The opening in the first branch constitutes a liquid inlet. A wall portion of the second branch spaced from the reaction zone is of self-sealing material which is punctured to release gas from the compartment and to aspirate liquid into the first branch. The material subsequently forms a fluid-tight seal. A wall portion of the body adjacent the reaction zone is made of light-permeable material so that the reaction or the result of the reaction can be optically analyzed. A plurality of such compartments can be provided with a chamber interconnecting the extreme ends of the second branches. A common wall portion of self-sealing material can then be provided for some or all of the compartments.