A disposable apparatus for use in blood testing and being adapted for simultaneous dilution of a blood sample into two different dilution ratios, said apparatus including a block-shaped housing having integrated therein a first and a second receptacle, one of which as a first blood sample receiver being adapted to receive a blood sample; a first and a second container, each containing a defined volume of a diluting agent; a valve including a valve body having three valve body channels extending therethrough and being positionable in three distinct positions, one of which putting the receptacles in simultaneous communication with a respective one of the containers through pairs of the channels; and displacers for displacing the diluting agent and the diluted sample through said channels between said containers and said receptacles.