An antibody fragment produced by papain treatment. Fab fragments (45 kDa) contain one antigen binding site and consist of one light chain (111 aa) linked through a disulphide bond to a portion (127 aa) of the heavy chain; they are effectively univalent antibodies. Fab(2) fragments (90 kDa) are produced by pepsin treatment and consist of two linked Fab fragments. They are divalent but lacks the complement-fixing (Fc) domain.
Subjects: Medicine and Health.