Protein expression and purification is widely used in disease biomaker production for qFLASH and amplification enzyme for mFIND, representing a crucial platform to make the key protein supply stable. Protein expression refers to the introduction of the nucleic acid sequence encoding the target protein into the host cell through genetic engineering technology, so that the proteins can be expressed in large quantities. Proteins are then purified in vitro using appropriate purification methods, so as to obtain high purity, activity and high yield of the proteins.

Compared to other expression systems, the E. coli expression system boasts several advantages, including a well-understood genetic background, high-level expression of target proteins, short cultivation periods, relatively simple and mature experimental techniques, low cost, and a wide variety of E. coli strains and compatible plasmid vectors with diverse characteristics available for selection.

The protein purification process is influenced by the physicochemical properties of the protein itself, and the success of purification is largely determined by the theoretical knowledge and experience of the technical personnel. In practical operations, the appropriate purification method can be selected based on molecular weight and electrical charge of proteins.