Abstract: A computer-controlled fluid manipulation and analysis apparatus for chemical, biochemical and clinical analysis, sample preparation, and microscale chemical and biochemical synthesis, having one or more stream selection hubs with multiple ports through which microliter volumes of multiple fluid streams may be accessed, stacked, mixed and otherwise transferred by two or more cooperant pumping systems in a highly repeatable and fully software programmable manner. The inherent or resulting properties of said fluids may be automatically recorded via one or more appropriate electronic detectors and data recording systems. Systems comprised of two or more hubs exhibit higher properties of a flow network, and allow more than one fluid segment to be processed simultaneously. Bi-directional flow may occur in each inter-hub connection, and a plurality of possible transport routes can exist between hubs. This leads to enhanced flexibility in sequential processing of each fluid segment.