Fragment antigen-binding region

The variable domain contains the paratope (the antigen-binding site), comprising a set of complementarity-determining regions, at the amino terminal end of the monomer.

The Fab abciximab, which inhibits blood clotting, works by disabling glycoprotein IIb/IIIa found on platelets.

Certolizumab pegol is a Fab chemically linked to PEG, and it treats various inflammatory disorders by binding away TNFα.

It is conjugated to a radioactive element, which will label the tumors when viewed with single-photon emission computed tomography.

[7] Fab fragments are often fused to small proteins (<100 kDa) that have lower scattering, resulting in images with less contrast.