Antibody-binding fragments

More sophisticated antivenoms, containing antibody binding fragments, are less immunogenic than whole antibody antivenoms, and seem safe and effective. 

Yarmush, M.L., X.M. Lu, and D.M. Yarmush (1992). Coupling of antibody-binding fragments to solid-phase supports site-directed binding of F(ab )2 fragments. /. Biochem. Biophys. Meth. 25 285-297. 

Our finding is also verified by Butler et al. (1977). Their initial premise was that, since Fab fragments are cleared primarily by the kidney, and antibody binding to digoxin can be detected... 

Figure 1.77 Disulfide reducing agents such as 2-mercaptoethylamine can be used to cleave the disulfide bonds in the hinge region of antibody molecules. Either intact IgG molecules or F(ab )2 fragments may be reduced in this manner to yield monofunctional antigen binding fragments.

Antibody affinity from the Latin, affinis = connected with, having things in common. In immunohistochemistry, antibody affinity determines the strength of binding of a monovalent antibody, such as Fab fragment, to one epitope, i.e., how tightly an antibody binds to its particular antigen. 

A reversible, direct fluoroimmunosensor for human serum albumin (HS A) measurement has been described by Bright et al.(m> Antibody Fab fragments are first immobilized on small quartz plates by hinge-region thiols, and then dansylated. The immunosensor is formed by attaching the quartz plates with bound Fab to the distal end of a bifurcated fiber-optic probe, which transmits both the excitation and emission. Binding of ffSA to the immunosensor results in a three- to five-fold enhancement of dansyl fluorescence. The sensor can be reused up to 50 times, with a detection limit of about 1.8 x 10-8 M, and a somewhat limited dynamic range. 

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