Abstract: An apparatus for determining the blood group of an individual. The apparatus comprises a carrier plate slidably mounted for horizontal movement and adapted to support an analysis holder. The analysis holder is provided with several series of cavities adapted to hold blood samples, agglutination reactants, and mixtures of the two for analysis. A block of distribution needles associated with pumping means is slidably mounted for vertical movement. The number of needles in the distribution block and the number cavities in each series in the analysis holder is the same. The movements of the block of distribution needles and of the carrier plate are synchronized, when initiated, so as to cause blood samples and reactants to be pumped from their respective cavities in the analysis holder through their corresponding needles to analysis cavities. Analysis is by optical density detecting means associated with means for displaying the analytical results.