The invention concerns a process for producing reagent carriers having a binding capability that are suitable for determining analytes in liquids, wherein the process comprises at least one step of treating a respective reagent carrier body in particular by transferring material between a treatment device and the reagent carrier body in a preparation device and wherein this treatment step takes place on the moving reagent carrier body during its transport in the preparation device or during a movement of the treatment device relative to the reagent carrier body in the preparation device.