According to the invention, generally, a microfluidic aliquoting (MA) chip, adapted to fit in a Petri dish, has a center well (inlet) connected by a plurality of microchannels to a plurality of side wells (outlets). A relatively large (such as 120 μL) cell suspension having several cells may be injected into the inlet of the MA chip, and single cells may be substantially simultaneously and uniformly distributed, via positive pressure-driving flow, to the several (such as 120) side wells having single cells in less than 1 minute. The MA Chip has a high efficiency in cell recovery. Due to rapid isolation and easy identification of single cells, high cell viability, high enrichment factor, and convenient transfer of submicroliter single-cell suspension, MA Chips are well compatible with CTC isolation from blood, single-cell cloning, PCR, and sequencing.