Principles of Cow Single B Cell Technology

Single B cell antibody production is a newly developed technology for rapidly producing monoclonal antibodies in recent years. Based on flow cytometry sorting technology, single B cell monoclonal antibodies are prepared, utilizing the characteristic that each B cell contains only one functional heavy chain variable region DNA sequence and one light chain variable region DNA sequence, and only produces one specific antibody. B cells are collected from animal lymphoid tissue, The heavy and light chain variable region genes were amplified from single antibody-secreting B cells using single cloning technology, thereby amplifying the collected B cells into a single source clone population. Then select the host for antibody production to produce monoclonal antibodies[1] .

Cow single B cell technology has outstanding advantages such as high specificity, high activity, and high affinity. Currently, antibodies produced by cow single B cell technology are widely used in biomedical research, diagnostic tools, and therapeutic drug development[2] .


Figure 1: Flow chart of cow monoclonal antibody product (KMD Bioscience)

Production process of cow single B cell monoclonal antibody

① Animal immunity and PBMC isolation. Cows are selected as experimental animals and are immunized 4-5 times by injecting a target antigen (usually a target protein or polypeptide) to stimulate an immune response, thereby activating the cow’s immune system and causing B cells to produce antibodies. Then ELISA assay, peripheral blood collection and PBMC isolation were performed.

② Flow sorting. Antigen specific single B cells were sorted by PBMC flow sorting method.

③ Single B cell culture screening. The single B cells were first cultured in 5-20 plates with 96-well plates in vitro, and then the supernatant of the cell culture was screened by ELISA or pre-interventional detection such as FACS.

④ Sequencing of positive clones. At least 20 positive cell clones were selected for RT-PCR to amplify their antibody variable region genes and then sequenced.

⑤ Vector construction, antibody expression and purification. Finally, the mammalian expression vector, cell transfection and ELISA were verification.

Figure 2: Flow chart of cow single B cell monoclonal antibody production (KMD Bioscience)

Advantages of single B cell monoclonal antibody production

Categories Single B Cell Technique Hybridoma Technology Phage Display Technology
Antibody Natural Natural Unnatural
Antibody Affinity High High Medium
Druggability High High Low
Time 16 to 20 Weeks, Optional Rapid Immunization 20 to 26 Weeks, Optional Rapid Immunization 16 to 20 Weeks, Optional Rapid Immunization
Antibody Gene Sequence Direct Acquisition Further Sequencing Required Direct Acquisition
Antibody Diversity High Medium Medium
The species that can be screened Unrestricted Species Mouse and Rabbit Unrestricted Species


Cow single B cell technology can quickly product monoclonal antibodies according to the characteristics of B cells, and directly obtain a complete single source of antibodies. This method has no restrictions on species, high efficiency, high specificity, high antibody affinity, high drug formability, good genetic diversity and all-natural origin, and can directly obtain antibody gene sequence[3] .

Application of cow single B cell monoclonal antibody production

Cow single B cell monoclonal antibody production are generally widely used in the following four aspects:

① Drug research and development. Cow single B cell monoclonal antibody product can be used in the research and development of new drugs, especially in the field of cancer therapy has great application prospects.

② Vaccine development. Cow single B cell monoclonal antibody product can be used to improve the efficacy and specificity of vaccines.

③ Immunotherapy. Cow single B cell monoclonal antibody product can be used in immunotherapy, enabling more personalized treatment for consumers.

④ Basic medical research. Antibodies are specific and diverse and can be used to resolve biological processes and disease mechanisms.

The services and advantages that KMD Bioscience can provide

KMD Bioscience has rich experience and strict quality control system. The production service of single B cell monoclonal antibody is short in cycle, unlimited in species, and antibody sequence can be obtained. The antibodies obtained have higher specificity and affinity. In order to meet the different needs of our customers, KMD Bioscience can provide one-stop technical services from antigen design, synthesis and modification, to animal immunization, phage library construction and screening, downstream antibody modification and application identification.


[1] Tan S H , Young D , Elsamanoudi S ,et al.Abstract 2565: Detection of ETV1 expression in human prostate tissue specimens using a novel and highly specific rabbit monoclonal antibody[C]//Proceedings: AACR Annual Meeting 2021; April 10-15, 2021 and May 17-21, 2021; Philadelphia, PA.2021.DOI:10.1158/1538-7445.AM2021-2565.

[2] Wallace J L , Arfors K E , Mcknight G W .A monoclonal antibody against the CD18 leukocyte adhesion molecule prevents indomethacin-induced gastric damage in the rabbit[J].Gastroenterology, 1991, 100(4):878-883.DOI:10.1016/0016-5085(91)90259-N.

[3] Powell, William C ,Hicks,et al.A new rabbit monoclonal antibody (4B5) for the immunohistochemical (IHC) determination of the HER2 status in breast cancer: comparison with CB11, fluorescence in situ hybridization (FISH), and interlaboratory reproducibility.[J].Appl Immunohistochem Mol Morphol, 2008,15(5):510-1. DOI:10.1097/PAI.0b013e31802ced25.