Rich repertoire of fully human antibody variable region:

Complete functional human Heavy Vs loci substitution in situ;

Complete functional human Kappa Vs loci substitution in situ;

Complete functional human Lambda Vs loci substitution in situ.

Normal B cell development comparable to wildtype littermate.

Complete absence of endogenous mouse Heavy, Kappa and Lambda gene segments.

High affinity (subnanomolar to picomolar) antibodies straight from the mice.