A collection of devices including an electrically-powered laboratory instrument, microfluidic cassette and control materials, intended to be used to separate and collect circulating tumour cells of a specified size and/or deformity from a whole blood specimen using a mechanical separation method (e.g., microfluidics). The instrument channels the blood specimen through the microfluidic cassette, where the circulating tumour cells are concentrated and contained for subsequent in vitro diagnostic analysis.