A device for conducting an agglutination assay comprising several reaction vessels, each reaction vessel comprising an upper chamber having an opening for accepting reactants and/or a sample; and a lower chamber comprising an end in communication with the upper chamber for receiving fluids from the upper chamber, a closed end opposite to the end, and a matrix for separating agglutinates from non-agglutinates; wherein the device further comprises a rotating support able to rotate around an axis and holding pivotally the reaction vessels in a way to allow the reaction vessels to pivot about an axis essentially perpendicular to the rotation axis of the support when the latter is rotated, such that the fluids remain in the upper chamber when the support is not rotated, and can flow from the upper chamber to the lower chamber and into the matrix when the support is rotated.