The true power of mAbs was unleashe

The true power of mAbs was unleashed in the late 1980s when the genes encoding the variable domains extracted from a population of B cells (i.e. antibody library) were able to be cloned [56,57], recombinantlyexpressed [32], andin vitrodisplayed [4]. Depending on their source of origin, antibody libraries come in several flavors: naïve, immune, semi-synthetic, or fully synthetic. Importantly, the functional diversity of an animalderived library is typically 107–8. Naïve and immune libraries are derived from non-immunized and immunized animals, respectively. Antibodies derived from immunized animals have the advantage of exploiting thein vivoaffinity maturation process; however, they are also dependent on immunodominant epitopes which may not be ideal as functional targets. Semi-synthetic libraries are a combination of donor-derived Ig sequences with synthetic diversity in all or some of the CDRs [58].