Abstract: The invention relates to a method and an apparatus for measuring the radioactivity of samples that are arranged in the wells of a microtitre plate and in which the radio-activity is solid-bound, for example cell-bound, or is in the form of a protein precipitate, wherein samples suspended, dissolved or mixed in liquids are first separated from the liquids and then their liquid supernatant is removed by suction. The invention comprises connecting the bases (4) of the wells of the microtitre plate to one another and then separating them from the microtitre plate or the well walls in such a manner that they remain connected, and subsequently measuring the samples they carry in succession, in groups or simultaneously over the entire grid.