FAB

Fab

 (fragment, antigen-binding)

originally, either of two identical fragments, each containing an antigen combining site, obtained by papain cleavage of the IgG molecule; now generally used as an adjective in terms such as Fab fragment or region, referring to an “arm” of any immunoglobulin monomer, i.e., one light chain and the adjoining heavy chain V_H and C_H1 domains.

digoxin immune Fab (ovine) a preparation of antigen-binding fragments derived from specific antidigoxin antibodies produced in sheep that have been immunized with digoxin coupled as a hapten to human serum albumin, used as an antidote to life-threatening digoxin and digitoxin overdose; administered intravenously.

FAB

Abbreviation for French-American-British (classification of acute leukemias). See: FAB classification.

alcopop

A popular term for any of the alternative beverages that were formulated in response to an increase in the US federal wine tax in the early 1990s. The spirits industry responded by moving away from wine coolers to malt-based alcoholic beverages including "hard" lemonades and fruit coolers and drinks.

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FANCB

A gene on chromosome Xp22.2 that encodes a protein of the Fanconi anaemia complementation group (here, complementation group B), the members of which are related not by sequence similarity, but rather by their assembly into a common nuclear protein complex.

FAB

Abbreviation for French-American-British classification system.

fab

The monovalent antigen-binding fragment of an antibody molecule obtained when the protein is digested with the enzyme papain. It consists of an intact light chain and the immediately-associated terminal and domains of a heavy chain.