Abstract: A microplate reader having a receiving apparatus for receiving a microplate having predefined dimensions and a multiplicity of wells, and an optical detector for detecting an optical radiation at respective individual ones of the wells of a microplate that in the receiving apparatus. The receiving apparatus is arranged to be movable in at least one spatial direction by a positioning mechanism to position the received microplate relative to the optical detector for successive measurements at different wells. The movable receiving apparatus has an interface device configured to provide an energy and/or data connection and/or a media supply connection and/or media disposal from the microplate reader to an accessory apparatus for additional functions. The interface device enables additional hardware provided as an accessory apparatus, which can be inserted into the receiving apparatus jointly with or instead of a microplate or some other sample container, to be supplied with energy and communication.