Anti-mouse Fab fragment

Another potential problem occurs if the anti-mouse Fab molecules do not block the mouse species-specific sites. Incubation with the mouse anti-Ag A and antimouse 488 fluorophore (Fig. 12.3a) is then blocked with normal mouse serum IgG (Fig. 12.3b, stippled gray). If there is insufficient anti-mouse Fab to block the mouse antibodies from the first set of incubations, then the second 2° antibody will bind to the first set of antibodies. Specifically, the second 1° antibody, mouse anti-Ag B, binds to the Ag B antigen (Fig. 12.3c). Then the lack of anti-mouse Fab fragments... 

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