The IgG molecule can be subdivided into two functional subunits: (1) the fragment crystallizable (Fc), which constitutes the tail of the antibody and interacts with cell surface receptors to activate an immune response, and (2) the fragment-antigen binding (Fab), which mediates antigen recognition. The Fc region comprises two pairs of constant domains (CH2 and CH3) from two paired heavy chains, whereas the Fab region consists of a variable domain followed by a constant domain from the heavy chain (VH and CH, respectively), which pair with a variable and constant domain from the light chain (VL and CL, respectively). Alpha Lifetech Inc. is capable of providing different species or different isotypes of native or synthesized Fab antibody libraries based on our mature phage display technology platform. Building up a high-quality antibody library with a large library size and high diversity has been crucial for the successful isolation of antibodies, it will result in the speed of antibody-drug discovery. Now Alpha Lifetech Inc.'s antibody discovery R&D team is proud to announce that we can develop a synthesized Fab library with independent clones over 10^11.