Antibodies are immunoglobulins. These proteins, shaped as an Y, are composed of 4 chains: two identical heavy chains and two identical light chains. The heavy chains are roughly double the size of the light chains. A heavy chain contains one variable domain (VH) and three constant domains (CH1, CH2 and CH3). In contrast, a light chain contains only one variable domain (VL) and one constant domain (CL).
For recognition of an epitope on a given target (i.e. the antigen), the important antibody regions are the variable domains (VH and VL). Together, they are referred to as the Fv region, or the antigen-binding site.
The constant domains form the Fc region. This region also defines the different antibody isotypes: IgA, IgE, IgM, IgG. Inside an organism, this region is responsible for modulating immune cell activity. In the case of antibodies as reagents, the Fc part is the one recognized by secondary reagents.
Recombinant antibodies are incredible flexible tools, and can be engineered in several different formats, other than classical IgG molecules.
The standard format of the custom-made ABCD antibodies is a mini-antibody, with the Fv antigen-binding domain (as a single chain, or scFv) fused to an Fc domain (scFv-Fc). The Fc portions can be rabbit IgG, human IgG1 and IgG2, mouse IgG1 and IgG2, or guinea pig IgG. For all practical purposes, a mini-antibody is essentially used as a standard IgG antibody (and can be used with all standard secondary reagents that recognize the constant heavy chain).
Other formats are also possible, such as: full IgG molecule, different isotypes (IgA or IgM), chromobodies (the scFv domain fused to a reporter protein, such as GFP).
We deliver 50-100 μg of non-purified cell supernatant (+0.02% sodium azide) produced in HEK293 suspension cells, growing in serum-free medium, transiently transfected with the expression vector coding for the antibody.
Custom-made antibodies, however, are produced with VERY different and unpredictable yields. In some cases, only low or very low amounts of antibody are produced.
Antibodies protected by active patents are not commercialized by us.