Purification of monoclonal antibodies that recognize SARS-CoV-2 proteins via precipitation with polyethylene glycol

Abstract

Coronavirus disease 2019 (COVID-19) is a global health pandemic characterized by the World Health Organization on March 11, 2020. One of the main points for its containment concerns the diagnosis of the disease. Among the available tests, those that use antibodies stand out. However, a purification process is necessary for antibodies to be used. Precipitation is one of the most traditional, low-cost bioproduct purification techniques, related to the principle of reducing the solubility of a solute in a solvent, which culminates in the formation of the precipitate in the medium under study. Polyethylene glycol (PEG) can precipitate biomolecules from a small increase in its concentration and has been shown to perform satisfactorily with monoclonal antibodies (mAbs). Thus, this scientific initiation project aims to evaluate the purification of anti-covid 19 mAbs, using precipitation with PEG, aiming at its later application in diagnostic kits. Antibody solubility curves will be determined using PEG of different molecular weight (1500, 4000 and 6000) at different pH values (6.0, 7.0, 8.0 and 9.0) to determine the most promising conditions for the batch precipitation. Resolubilization conditions will be determined to obtain a mAb with purity greater than 98%. Parameters such as selectivity, yield and purity will be determined using quantification of mAbs and molecular exclusion in HPLC. This project will contribute to the scientific literature and to the industry that operates in the research and development segment in this field, which use classic and expensive systems for the purification of antibodies, a key component in diagnostic kits. (AU)