A mains electricity (AC-powered) laboratory instrument intended to be used for the processing of a prepared clinical specimen with an immobilized probe on a solid phase (e.g. blotting membrane or gel sheet) for blot assays (e.g. line assays, Western, Southern and/or Northern blot). It typically performs pre-analytical steps including (but not limited to) reagent dispensing, incubation (with or without heating), agitation and washing. The device does not include a detector and is not intended to perform qualitative and/or quantitative measurements.