The present invention provides a system and process providing variable access to, as well as quick and accurate dispensing of, numerous selected reagents from a mass storage arrangement. According to one embodiment, an array of reagent dispensers is supported over a movable platform assembly. The platform assembly aligns a designated receiving receptacle under a selected dispenser of the array so that a respective reagent can be dispensed therein. Advantageously, the apparatus and process can be carried out under the control of a programmed computer.