Abstract: In a method and apparatus for analyzing a liquid sample, particularly a sample of blood, in different concentrations, a portion of a sample contained in a sample receptacle (P) and diluted to a predetermined concentration is again diluted to a predetermined lower concentration when it is transferred to a receiving vessel (20) in which the sample is analyzed in respect of one or more sample parameters. The transfer is effected by a pipette (17) which in a first position (B) thereof is brought together with the sample receptacle (P) for aspiration of said sample portion and which is then shifted to a second position (A) for dispensing the portion and liquid diluent to the receiving vessel (20).

Abstract: An apparatus and method for serial dilution of liquid samples comprises a power-driven measuring valve having a rotatably mounted valve body provided with a single calibrated measuring passageway. During a dilution cycle the measuring passageway in different rotational positions of the valve body successively isolates a measured volume of a sample to be diluted and an equal volume of a first diluted solution of the sample which has been prepared by mixing the isolated undiluted volume of the sample with a measured volume of diluent. In a valve body position between said different rotational positions the measuring passageway is connected to form part of a rinsing flow system.