Strains and Media

Cell banks of Escherichia coli transformants A and B，as well as fermentation cell line F，carried plasmid pIL-2（4.56 kb in size）with integrated IL-2（interleukin-2）coding sequence.R2Bl growth medium contained 20 g tryptone，10 g yeast extract，10 g NaCl，and 1 mg vitamin B1per 1 liter medium.(https://www.daowen.com)