<prompt> Widal test is -Slide flocculation testImmunodiffusionTube precipitationTube agglutination  <response>: Ans. is d i.e., Tube agglutination Agglutinationo When a particulate antigen is mixed with its antibody in the presence of electrolytes at a suitable temperature and pH, the particles are clumped or agglutinatedo Agglutination is more sensitive than precipitation for the detection of antibodies.Agglutination testsSlide agglutinationTube agglutinationCoombs testPassive agglutination testo Blood grouping and cross - matchingo Widal testo Weil - felix reactiono Paul Bunnell testo Cold agglutination testo Streptococcus MG agglutination testo Anti - Rh antibody test Haemagglutinationo Rose Waaler test for R. A.Latex agglutinationo Detection of: ASO CRP RA factor HOG 