Fab consists of a light chain (VL + CL) and a heavy chain (VH + CH1), connected by an interchain disulfide bond. It comprises 440-450 amino acids with a molecular weight of approximately 55 kDa. Fab offers advantages including small size, high tissue distribution specificity, and low immunogenicity, leading to its extensive application in medical fields such as disease prevention, diagnosis, and therapy. Additionally, due to its good permeability, Fab antibodies are widely used across various research areas including immunohistochemistry, immunofluorescence, and flow cytometry etc. Fab antibodies are typically prepared using Phage Display Libraries, enabling the screening of Fab antibodies with high affinity and specificity within a short time frame.

KMD Bioscience possesses extensive industry experience in phage display antibody library construction and screening, dedicated to producing ideal recombinant antibodies for clients. We offer specialized Fab Phage Screening technology and are pleased to provide efficient Fab Antibody Screening strategies. We construct both natural and immune Fab Phage Antibody Libraries for clients, featuring large capacities and high diversity. By cloning Fab genes into phage vectors followed by transformation, we establish Fab Phage Display Libraries. Through 2-3 rounds of panning, Fab antibodies with strong binding capacity and high affinity can be isolated within approximately 10 days, significantly shortening experimental timelines and facilitating overall project advancement. We can directly screen pre-made Fab Natural Libraries without animal immunization, accelerating Fab preparation. Additionally, we conduct screening across various phage libraries (including M13, T4, T7, and λ) per client requirements, with species sources spanning human, murine, rabbit, chicken, ovine, and camelid. Typically, 4 rounds of library screening enable selection of Fab antibodies with 10^-8 affinity.

KMD Bioscience specializes in the development of Phage Display and Screening technologies, utilizing comprehensive biological screening strategies and advanced laboratory equipment to provide optimal Phage Screening services for global clients. We are adept at creating customized solutions for clients to screen for satisfactory Fab antibodies. We excel at screening large Phage Fab Antibody Libraries. For M13 Phage Display, we fuse the Fab fragment to the filamentous phage g3p coat protein, enabling the selection of Fab antibodies with strong antigen affinity. Using an ELISA-based method, we immobilize the antigen and retain recombinant phage binding to it through biopanning, while washing away weakly bound phage. The remaining binding-competent recombinant phage are separated from the antigen via acid elution and used to infect E. coli. Helper phage are then employed to infect the E. coli clones expressing phage, allowing collection of antigen-binding Fab Phage Antibodies. Repeated rounds of phage screening and amplification enrich for antigen-binding antibodies. Throughout the screening process, Phage ELISA serves as our primary method for confirming positive clones.