Antibodies are one of the most widely-used tools in biological sciences. However, they are also one of the major causes of the reproducibility crisis plaguing bio-medical research. Reproducibility involves the ability to repeat experiments with reagents identical to those used by previous researchers. 

In the case of antibodies, it is almost impossible to guarantee the use of identical reagents. Polyclonal antibodies (pAbs) are a variable mixture of several undefined antibodies produced by immunization of an animal. Monoclonal antibodies (mAbs) are produced ex vivo from a single clonal cell line (called hybridoma), isolated from an immunized animal. However, hybridomas are not always a homogeneous cell population, and in one-third of cases additional antibody genes might be present. This is an enormous problem in terms of specificity, affinity and reproducibility.

The only way to guarantee the identity of an antibody reagent is by knowing its aminoacid sequence. Antibodies with known sequences are produced in vitro, and referred to as chemically-defined antibodies, or recombinant antibodies (rAbs). rAbs are characterized by controlled production, high reproducibility, high batch-to-batch consistency, long-term supply (as the sequence information cannot be lost), and the possibility of endless antibody engineering.

All antibodies produced by ABCD antibodies are recombinant.