Abstract: A dosing and mixing apparatus for fluid media comprising at least one delivery element and one isolating element. These elements are provided with through-flow or transfer passages and dosing chambers suitably mutually arranged for accomodating and isolating a voluminized specimen quantity or measured dose of test specimen as well as for delivering this measured out dose of test specimen to and mixing this dose of test specimen with a measured dose of thinning agent. The dosing and mixing apparatus manifests itself in that at least one channel suitably associated with the dosing chamber is provided in a surface of one of the elements, such as the isolating element at the surface thereof which faces the delivery element. Each such channel communicates with through-flow openings or circulation passages and is traversed by a cleansing fluid wetting the mutually facing and touching surfaces of the individual delivery and isolating elements in the transport path of the dose of test specimen.

Abstract: An apparatus for the detachable connection of an axially to-and-fro movable piston of a syringe with a piston rod or plunger, comprising at least two holder brackets arranged in mutually spaced relationship from one another at the piston plunger and formed of a spring wire, detachably secured with said piston plunger. Each holder bracket essentially comprises two respective axially extending webs and a connection element or piece arranged transversely with respect to said webs. The piston of the syringe possesses a headpiece formed as a substantially truncated cone and equipped with a contact edge engaged by said connection pieces.