It is necessary to isolate single B cells that can target specific antigens from immunized mice. When conducting Mouse Single B Cell Sorting, the selection and handling of mice are important, and healthy mice with normal immune function should be selected. Before sorting, mice need to be treated appropriately, such as rapid neck amputation to avoid splenic infarction, and they should be soaked in 75% alcohol for disinfection. After separation, the spleen should be placed in a sterile ring. According to the number of spleen cells, an appropriate grinding method should be selected to obtain sufficient cell suspension. Cells need to be washed to remove impurities and red blood cells. The cell concentration is generally adjusted to 100x10 ^ 6/500 μl. B cells in peripheral blood or spleen are enriched to improve sorting efficiency. By using facs cell sorting to selectively sort enriched B cells, based on the expression patterns of cell surface markers, facs cell sorting can efficiently identify B cells. The sorted individual B cells are lysed to release their nucleic acids. The mRNA inside the cell is reversed by RT-PCR, and primers are designed based on the genes of the variable heavy chain and variable light chain of the target antibody. The variable region sequence is then amplified by PCR. On this basis, NGS sequencing was used to sequence and analyze the antibody variable region genes encoded by these B cells, in order to obtain their gene sequence information. The variable region sequence was inserted into a vector plasmid containing a constant region gene, and a plasmid expressing monoclonal antibodies was obtained. According to the requirements, a suitable expression system is selected to obtain antibodies, and antibody labeling and other operations can be performed on the obtained antibodies.

With the continuous development of technology, single B cell technology has been used in more and more fields. Single B cell technology can be used to prepare antibodies against specific pathogens, such as HIV antibodies, tetanus antibodies, hepatitis B antibodies and influenza antibodies, for disease prevention and treatment. Single B cell antibody technology can isolate specific B cells targeting tumor antigens and prepare efficient anti-tumor monoclonal antibodies, which can be used for tumor diagnosis and treatment. By isolating B cells targeting pathogen antigens, efficient and specific vaccine candidate antigens can also be prepared, which is helpful for vaccine development. Taking mouse single B cells as an example, through mouse single B cell sorting, B cells that only respond to specific antigens can be screened from a large population of B cells in immunized mice. The antibodies produced by these B cells have high specificity and affinity, and can be used for antibody discovery. Traditional methods for antibody discovery take longer and are more expensive, while mouse single-cell sorting technology can shorten the time required for antibody preparation. After obtaining specific B cells in mice, the gene sequence of antibodies can also be quickly obtained, and recombinant antibodies can be constructed. Mouse single-cell sorting technology can also be used to study human B cell responses. When tumor specific B cells in cancer patients are sorted out, antibody drugs targeting specific tumor antigens can be prepared for targeted therapy. In addition, mouse single-cell sorting is beneficial for studying the functions and mechanisms of the immune system, such as the laws of B cell development and differentiation, as well as the regulatory mechanisms of immune response.