Abstract: A multi-stage dilution device, comprising a first stage dilution apparatus (A), and a second stage dilution apparatus (B), each of the stage dilution device comprising:—(i) a housing (1) having a diluent inlet (7); (ii) a sample inlet (2) having a sample introducer within the housing (1) adapted to introduce the sample at an introducer point (4) within the housing (1); and, (iii) a mixing conduit (5) mounted at least partially within the housing (1), the mixing conduit (5) having an inlet section comprising a mouth (10), and a fluid outlet (8), and a throat section (9) capable of producing a pressure drop within the mixing conduit (5), the pressure drop being sufficient to draw sample through the sample inlet (2); the introducer point (4) of the sample inlet (2) being proximate the mixing conduit inlet; and wherein the fluid output (8) of the first stage dilution apparatus (A) is in communication with the sample inlet (2) of the second stage dilution apparatus (B).