An apparatus for opening and closing a container having a slidable shutter closure moving past the apparatus includes: a rotatable shaft having an axis perpendicular to the direction of travel of the slidable shutter, the shaft being biased against rotation in either direction; a driver for bidirectionally moving the shaft from a position away from the container to a position in the vicinity of the container for opening and closing; and an extension extending outwardly from the rotatable shaft along at least a portion of the shaft into a line of travel, whereby the extension is adapted to engage the shutter closure of the container and move the shutter closure from an open position to a closed position or from a closed position to an open position. A reagent source for an automated analyzer includes: a reagent source which includes a container having a shutter closure which slides between an open and closed position; an apparatus for opening and closing the container. The apparatus includes: a rotatable shaft having an axis perpendicular to the direction of travel of the slidable shutter, the shaft being biased against rotation in either direction; a driver for bidirectionally moving the shaft from a position away from the container to a position in the vicinity of the container for opening and closing; and an extension extending outwardly from the rotatable shaft along at least a portion of the shaft, whereby the extension is located to engage the shutter closure of the container as the container is transported past the extension; and a bidirectional conveyor for transporting the container into engagement with and past the apparatus for opening and closing.