The present invention relates to a process for the production of catalysts, particularly of Ziegler-Natta type of catalysts for olefin polymerisation, to the catalysts as such, and to their use in polymerising olefins. The devices and methods of the invention can be used for the simultaneous diagnosis of multiple diseases by detecting molecules, such as polynucleotides or proteins, by measuring the signal of a detectable reporter associated with hybridized polynucleotides or antigenantibody complex. The cover structure includes a recess for receiving a pullcord of the like, and a receiver adapted to couple with a rod for controlled pivoting of the cover structure and release of the magnetic connection between the magnetic pairs.