Phage Display Antibody Library Technology-Special Topic on Phage Display Technology-Tekbiotech-Yeast Display Service,Phage display technology

Phage Display Antibody Library Technology

Phage display antibody (PDA) library is another tool for isolating monoclonal antibodies. This technology is widely used in antibody research and development around the world, and has produced more than 80 antibodies that have entered clinical trials. The technology involves creating large combinatorial pairs of variable heavy chain and light chain antibody libraries and expressing them in fusion with a coat protein on the surface of phage. Many antibodies can be identified from a single library, further expressed and produced in prokaryotic expression.

1.Advantages of Phage Display Antibody Library

This technology has advantages over other isolation technologies due to the robustness and high stability of phages. Phages can withstand extreme conditions of denaturants, pH, high temperature, UV light, and other factors such as non-aqueous solutions, proteolytic enzymes, etc. This feature allows the isolation of different types of antibodies that are stable or minimally affected by harsh environments. Therefore, in phage display technology, conditions and selection pressures can be adjusted as required, and selection methods that are impossible in live antibody production can be mastered.

2.Characteristics of Different Antibody Types

Antibody Type	Size（kDa）	Antibody Binding Site （valence）	Fc-mediated Function
IgG	150	2	√
ScFv	28	1	×
Fab	50	1	×
F（ab）2	110	2	×
ScFv-Fc	110	2	√
Diabody	55	2	×
VHH	15	1	×

3.Phage Display Antibody Library - Immune Library

Immune phage libraries are constructed from messenger RNA of IgG genes. These immune libraries are rich in antigen-specific antibodies, which are prone to recognize certain targets or antigens. A large number of antibodies with different specificities against different epitopes can be isolated from the same immune library. Immune phage libraries can be constructed from infected patients, individuals who have recovered from infection, or from peripheral blood mononuclear cells (PBMC), bone marrow, lymph nodes, spleen or spleen from vaccinated individuals. A major advantage of constructing immune phage libraries from these individuals is that binders with very high finiteness can be directly isolated from these libraries and can be directly used for different therapeutic applications. A single immune library constructed from these individuals can also be used to isolate antibodies against multiple epitopes/targets of the same pathogen, and sometimes for different pathogens.

Due to ethical issues related to human immunity, this problem can be overcome by immunizing transgenic animals (xenogeneic mice) that express human antibody repertoires. The B cells of these animals produce human-like antibodies. The mRNA of these mice can be directly used to construct immune libraries. The main advantage of these immune libraries is that the antibodies produced will be of very high quality and high affinity. In vivo, the immune response can be replicated in vitro in the form of immune phage libraries. These phage libraries can be used to isolate antibodies against secondary or local immunogenic areas. The size of the immune library is relatively small because the immune system has already encoded the target antigen; therefore, a large number of antibodies with the desired affinity can be isolated from such a library. The main disadvantage of the immune library is that it requires immunization, and sometimes the immune response triggered is either unpredictable or irreversible.

TekBiotech has built a complete antibody platform. We have mature hybridoma technology and can use phage display antibody library technology to prepare monoclonal (poly)clonal antibodies of different species. We also provide antibody purification, antibody labeling, antibody humanization, affinity determination and other diverse technical services.

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