Abstract: A rotary shear valve comprising two stators and a rotor is filled with specimen in a first rotary position. Movement of the rotor to a second rotary position divides the specimen into aliquots, one or more of which are dispensed in the second rotary position. A cleaning cycle is provided in which cleaning solution is introduced, with the rotor in a third rotary position, into circumferentially-extending arced grooves formed in the rotor faces, which contacts in the third rotary position those portions of the rotor faces likely to contain smeared specimen. The requirement for disassembly for cleaning is thereby reduced.

Abstract: A system that is particularly useful in biological fluid analysis includes a face plate member and a mating flexible member, one of which has a plurality of passages. Selected motion of the flexible member provides a valving action to control fluid flow into, through, and out of the passages. An analysis chamber in a surface of the face plate member is in fluid communication with a passage and has an analyzer which, for a hematology analyzer, is preferably an impedance-type particle counter.