A flow cytometry apparatus includes a flow cytometer having a suction or negative-pressure intake probe, a support for a microplate having a plurality of sample wells, and motive elements operatively connected to at least one of the probe and the support for moving the intake probe and the support relative to one another so that the intake probe is sequentially aligned with different sample wells of the microplate. The apparatus has no fluid pumping elements between the support and the flow cytometer so that a bubble-separated sample stream is forced to the flow cytometer solely by virtue of a negative pressure communicated via the intake probe.