Application of monoclonal antibodies

Application of monoclonal antibodies

Since the advent of monoclonal antibodies, due to their unique characteristics, they have been rapidly used in many fields of medicine. Mainly manifested in the following aspects:

1. Test medical diagnostic reagents

As a diagnostic reagent in the testing medical laboratory, monoclonal antibodies are widely used in enzyme-linked immunosorbent assay, radioimmunoassay, immunohistochemistry, flow cytometry and other technologies due to their advantages such as strong specificity, high purity, and good uniformity. And the application of monoclonal antibodies has greatly promoted the development of commercial kits. At present, commercial kits made with monoclonal antibodies are widely used in: ① detection of pathogenic microorganism antigens and antibodies; ② detection of tumor antigens; ③ detection of immune cells and their subgroups; ④ hormone determination; ⑤ measurement of cytokines .

Monoclonal antibodies recognize antigens very differently than polyclonal antibodies. Different kits use different monoclonal antibodies and different antigen recognition sites, resulting in some differences in test results. Therefore, the issue of standardization needs further study.

2. Purification of protein

Monoclonal antibodies are important ligands in affinity chromatography. The monoclonal antibody is adsorbed on an inert solid phase matrix (such as Separose 2B, 4B, 6B, etc.) and prepared into a chromatography column. When the sample flows through the chromatography column, the antigen to be separated can specifically bind to the solid phase monoclonal antibody, and the remaining components cannot bind to it. After the chromatography column is fully eluted, the ionic strength or pH of the eluent is changed, the antigen to be separated is dissociated from the antibody, and the eluate is collected to obtain the antigen to be purified.

3. Application of small molecule antibodies

The monoclonal antibody directed against a certain tumor antigen is connected with the chemotherapy drug or radiotherapy substance, and the guidance effect of the monoclonal antibody is used to carry the chemotherapy drug or radiotherapy substance to the target organ and directly kill the target cell, which is called tumor-directed therapy. In addition, the radioactive marker is connected to the monoclonal antibody and injected into the patient to perform radioimmunoimaging to assist in the diagnosis of the tumor. Small molecule antibodies are small molecular fragments with antigen-binding functions. It has the following unique advantages: small molecular weight, strong penetration, low antigenicity; because it does not contain Fc segment, it will not bind to cells with Fc segment receptors, and there are few adverse reactions; short half-life is conducive to timely neutralization And remove toxins; in addition, it can be expressed in prokaryotic system and easy for genetic engineering operation.

4. Application of antibody fusion protein

1. Diagnosis of tumor in vivo imaging Single-chain antibody has a fast elimination rate and strong penetration, so the distribution index in tumor tissue is higher than that of intact antibody molecules. In radiographic imaging, radionuclide elimination is faster, the degree of harm to the body is small, and the background of imaging is low. Therefore, it is an ideal diagnostic carrier for imaging positioning and provides a new way for the diagnosis of tumors.

2. Diagnosis of viruses and antiviral infections Single-chain antibodies provide new and highly effective immunologic agents for the diagnosis and treatment of medically difficult diseases such as viral diseases. Therefore, it is particularly important for immunotherapy and diagnosis

Diagnosis of blood diseases Anti-human leukemia single-chain antibodies can be used for immunodiagnosis and typing of leukemia.