noun
agglutination reaction
Technical term used in immunology and laboratory medicine for the clumping of particles such as cells or latex beads due to antigen-antibody binding.
血液型の判定には凝集反応が利用される。
Agglutination reactions are used for blood typing.
凝集 means 'agglutination' or 'clumping' in general, while 凝集反応 specifically refers to the immunological reaction.
Compound of 凝集 (ぎょうしゅう, 'agglutination') and 反応 (はんのう, 'reaction').