To select a suitable chromatography medium and chromatography mode, we need to clarify the purpose of chromatography and the isoelectric point PI (charge property) of the target product. The PI of the target product can be obtained by calculating the target product sequence (theoretical isoelectric point), or by capillary isoelectric focusing electrophoresis (CIEF) (actual isoelectric point). Separation of substances based on the difference in charge between the target product and impurities in a buffer with a specific pH value. According to different chromatographic purposes, two modes can be selected for the ion exchange chromatography process: (1) flow-through mode: the target product does not bind to the packing material, and impurities are bound to the chromatography packing material as much as possible; (2) combined elution mode : The target product is combined with the filler, and then eluted with a certain concentration of salt.
Ion exchange chromatography is a chromatography method that separates substances according to the difference in charge properties of different biomolecules. The ion exchange chromatography medium is composed of agarose/dextran/polymer matrix coupled with ligands with positive and negative charges. The medium with negative charge is called cation exchange chromatography medium, which can bind positively charged proteins; the medium with negative charge is called anion exchange chromatography medium, which can bind negatively charged proteins.
The chromatographic medium manufacturing facility for Bio-Link is situated in Lanzhou City, Gansu Province, and spans a total area of more than 7,000 square meters. The factory is in charge of producing purification and cell culture items such chromatography packing materials and microcarriers, with a total investment of more than 100 million yuan and close to 100 workers. The base now contains a production line for 500L and 1000L chromatography packaging, as well as a well-equipped laboratory for quality testing (which has earned ISO9001:2015 quality management system accreditation). The plant's 80,000 liters per year total capacity is envisaged.