Automated apparatus for immunological assay

Automatic apparatus for immunological assay comprising means for supporting, guiding, and displacing sets of reaction wells stepwise along a path comprising a predetermined number of positions, means for supporting samples to be analyzed, means for supporting reagents, means for taking determined quantities of samples and of reagents and for injecting these quantities into the reaction wells, and means for washing the wells, means for reading results of the assay, and means for feeding sets of reaction wells and for rejecting used sets of wells, wherein the path for the sets of reaction wells is rectangular in shape comprising two long sides defined by parallel rectilinear rails for supporting and guiding sets of wells, and two short sides defined by means for displacing sets of wells transversely through three positions comprising two end positions on the long sides of the above-mentioned path and one intermediate position which constitutes an ejection position for a used set of wells and a feed position for a new set of wells.