<prompt> Which of the following is agglutination test -Widal testVDRLAscolis testKahn test  <response>: Widal test is a tube agglutination test. 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. two antigens, flagellar H antigen a, d somatic O antigen are used in Widal test. Reference : Anathanarayan panikers 9th edition, pg no:108,109 p 