<prompt> Agglutination test is -ABO incompatibilityVDRLWeil-felix testFTA-ABS  <response>: Weil- Felix reaction for the diagnosis of typhus fever. - The Agglutination reaction is when a paiculate antigen is mixed with its antibody in the presence of electrolytes at a suitable temperature and pH, the paicles are clumped or agglutinated. Reference : Anathanarayan panikers 9th edition, pg no: 108,109 p 