ABexpress-An antibody discovery platform based on single B cell sequencing

What is ABexpressplatform

Monoclonal antibodies play an important role in the fields of modern biology, medicine and pharmaceuticals. The current monoclonal antibody preparation technologies include hybridoma technology and phage display technology.

However, various forms of antibody discovery have certain limitations. For example, the basic process of murine hybridoma monoclonal antibody technology is to fuse B cells from immunized mice with myeloma cells, and then screen out that they can proliferate indefinitely. Mouse hybrid fusion cells that can secrete antibodies, but there are disadvantages such as low success rate of cell fusion and loss of chromosomes. Phage display technology can get rid of the B cell fusion process, but the obtained antibody may undergo conformational changes and then lose its affinity for the antigen, and due to the random combination of antibody heavy and light chains, the natural pairing of antibody heavy and light chains cannot be maintained .

 In order to obtain diverse natural antibodies quickly and efficiently, Icartab has developed the ABexpressR platform, which is a technology based on flow sorting, in vitro cloning and expression of antigen-specific B cell antibody genes-through different flow cytometry Combine antibodies and target antigens to sort out single B cells that have affinity for target antigens; clone a single B cell antibody-encoding gene and construct an expression vector by PCR technology. After transfecting the tool cell line, the cell culture supernatant can be verified Whether there is an antibody with affinity to the target antigen in the solution. This method can avoid the many inconveniences caused by hybridoma and phage technology, and the obtained antibody retains the natural pairing of the variable region of the light and heavy chain, and has the characteristics of good gene diversity, high efficiency, short cycle, and suitable for any animal antibody screening. At present, we have used this platform to screen a variety of antibodies including murine monoclonal antibodies, rabbit monoclonal antibodies, fully human monoclonal antibodies and nanobodies .


Illustration: The process of screening antibodies based on the ABexpressR platform, this platform can omit cell fusion or phage library construction and other technical processes

Why choose ABexpress R platform

This method retains the natural pairing of the variable regions of the light and heavy chains, and has the characteristics of good gene diversity, high efficiency, and suitable for antibody screening in any animal. It can avoid the problems of false positives or non-specific binding in the process of using phage library to screen monoclonal antibodies, can greatly accelerate the speed of monoclonal antibody screening, and is suitable for large-scale monoclonal antibody drug screening.


Hybridoma technology

Phage Technology

  • Cover all target-specific antibody secreting cells produced by immunized animals

  • Get accurate antibody gene coding sequence in one step in as short as six weeks

  • The platform can be extended to monoclonal antibodies or nanobodies of any animal

  • High throughput, 100+ different candidate antibodies can be obtained at one time


  • Hybridoma fusion efficiency is low, and many B cells cannot form stable fusion strains

  • Large-scale cell culture, high preparation cost

  • Due to the limitation of myeloma cells, only murine monoclonal antibodies can be prepared

  • Staff training time is long, workload is large, and throughput is low

  • Long monoclonal antibody preparation process (8-10 months)

  • Hybridoma cells are unstable and easily lead to loss of antibody genes


  • During the phage construction process, there is no guarantee that the phage library will cover all sequences

  • The wrong structure may appear during the antibody display process, and the antibody cannot bind to the target antigen

  • Non-specific binding of phage to target cannot be avoided

  • The panning workload is huge, and the number of candidate antibodies obtained is small