Abstract: A molded flexible fluid conduit and a make/before break pinch valve including a slidably movable pressure member spring biased normally against said conduit in closed condition of the valve, said conduit including a pair of elongate longitudinal unitary purchase formations capable of cooperating with slots carried by the valve whereby the conduit forcibly is pulled or stretched in diametrically opposed directions upon actuation of the valve subsequent to periods of closure so as to force the conduit open to permit flow.

Abstract: A sample feeding arrangement which receives sealed sample tubes, moves them one at at time to a seal piercing and sample aspiration station, and then discharges the used tubes. This sample feeding arrangement is mounted inside a sample analyzer of the type which previously had operated semiautomatically. Receipt of a sample tube at the infeed station of this feeding arrangement initiates the repositioning of the tube to an aspiration station, which thereat enables all other handling steps of the tube, sample aspiration, and the full system cycle of the analyzer.