Abstract: An apparatus for the transfer of a very small defined quantity of a specimen from an outer space to a reagent contained in a test chamber via a transfer slide mechanism that is displaceably disposed in a housing bore embodied as a sealing seat and that is provided with a channel that establishes the specimen quantity and is embodied as a capillary tube. The channel is adapted to be moved out of the filling position, where it is disposed in front of a receiving opening that communicates with the outer space in order to fill the channel with the specimen quantity, and into a test position in such a way that at the same time the receiving open is closed by the slide mechanism and the specimen quantity is introduced into the test chamber in order to empty the channel.