What is plasmid 

A plasmid is a small circular DNA molecule found in bacteria and some other microscopic organisms.Plasmids are physically separate from chromosomal DNA and replicate independently. They typically have a small number of genes-notably,some associated with antibiotic resistance-and can be passed from one cell to another. 

Plasmid is one of the key steps in the production of cell drugs such as CAR-T cells, which involves complex processes such as production, purification and analysis. 

Quality control of plasmid technology

Quality control of the plasmid technology is a key process to ensure that the produced plasmids meet the intended purpose ands be safe, effective and consistent. The quality control items of the plasmid technology mainly including pH value, appearance, identification, plasmid concentration/content, purity (260/280, ratio of superhelix ), residual host cell DNA , residual host cell RNA, residual host cell protein, sterile/bacterial endotoxin, etc.