The present disclosure relates to an analytical system with at least three components: a multiwell plate on which the wells are included in an optically transparent area; a frame holding the multiwell plate close to its edge while permitting the plate a certain extent of freedom of movement; a baseplate to which the multiwell plate, but not the frame is firmly fixed via a docking mechanism, such that different expansion of plate and frame can be compensated. A second aspect described herein relates to a method of docking a corresponding multiwell plate held by a frame to a baseplate and subjecting the multiwell plate to a step of a biological or chemical assay within this arrangement.