1.Principle of Single B Cell Antibody Generation Technology

As a next-generation antibody development technology, single B cell antibody technology enables the efficient and rapid isolation of antibodies from individual B cells, representing another breakthrough in antibody production following hybridoma and phage display technologies.This technology is based on the principle that each B cell carries only one functional heavy chain variable region DNA sequence and one light chain variable region DNA sequence, producing a single specific antibody. By collecting B cells from animal lymphoid tissues, the heavy and light chain variable region genes are amplified from individual antibody-secreting B cells through monoclonal techniques, expanding the collected B cells into clonal populations of single origin. Subsequently, an appropriate antibody production host is selected to express the genes in mammalian cells, yielding biologically active monoclonal antibodies.Single B cell technology offers outstanding advantages, including high specificity, high activity, and high affinity. Currently, antibodies generated using this technology have broad applications in biomedical research, diagnostic tools, and therapeutic drug development.

2. Single B Cell Antibody Preparation Process

① Animal Immunization and PBMC Isolation. Rabbits are selected as experimental animals and immunized by injecting the target antigen (typically a target protein or peptide) to induce an immune response. The rabbits are immunized 4–5 times to activate their immune system, prompting B cells to produce antibodies. Subsequently, ELISA titer determination is performed, followed by peripheral blood collection from the immunized rabbits and PBMC isolation.

② Flow Cytometry Sorting. Antigen-specific single B cells are sorted using flow cytometry with PBMCs.

③ Single B Cell Culture and Screening. The sorted single B cells are first cultured in vitro across 5–20 96-well plates. The supernatant from the cell culture is then screened via ELISA or subjected to preliminary detection methods such as FACS.

④ Positive Clone Sequencing. At least 20 positive cell clones are selected for RT-PCR to amplify their antibody variable region genes, followed by sequencing.

⑤ Vector Construction, Antibody Expression, and Purification. Finally, mammalian expression vectors for the antibodies are constructed, followed by cell transfection and ELISA validation.

3. Advantages of Single B Cell Monoclonal Antibody Production

Single B cell technology enables rapid monoclonal antibody production by leveraging the unique characteristics of B cells, allowing direct acquisition of complete single-source antibodies. This method offers numerous advantages: species independence, high efficiency, superior specificity, strong antibody affinity, excellent druggability, robust genetic diversity, and fully natural origin. Additionally, it provides direct access to antibody gene sequences.

4. Applications of Single B Cell Antibody Production Technology

Application in Antiviral Therapy: Single B cell antibody technology enables the isolation of individual B cells from human blood, allowing rapid identification and expression of antibody genes. This is particularly valuable for the treatment and prevention of emerging viruses. Globally, 63.9 million people are infected with HIV, and five anti-HIV envelope protein antibodies obtained through single B cell technology are currently being evaluated in Phase I/II clinical trials.

Application in Neurological Disease Treatment: The migraine drug Vyepti is a rabbit-derived antibody drug developed using single B cell technology. It targets and binds to the calcitonin gene-related peptide (CGRP) ligand, blocking its interaction with receptors. Additionally, another migraine drug from the same company, ALD1910, is in the preclinical research stage.

Application in Immune Disease Treatment: Single B cell antibody preparation technology holds great promise for researching therapeutic antibodies for autoimmune diseases and other immune system disorders.

5. Services and Advantages Offered by KMD Bioscience

KMD Bioscience (or Kameide Biotechnology) possesses extensive expertise, a rigorous quality control system, and offers single B cell monoclonal antibody development services with short turnaround times, no species restrictions, and obtainable antibody sequences, resulting in antibodies with higher specificity and affinity.To meet diverse client needs, KMD Bioscience provides one-stop technical services, ranging from antigen design, synthesis, and modification, to animal immunization, phage library construction and screening, and downstream antibody engineering and functional characterization.