DNA Transfection into Cultured Cells (In-Vitro)

Scientists used Chinese hamster ovary cultured cells and exposed them to ultrasound in the sterilized polyethylene chambers. They did this experiment to observe the cell lysis, sonoporation, and DNA in-vitro transfection. Scientists take the 10% albunex, which is air-filled human albumin, and ultrasound contrast which is gas-based, to ensure the cavity nucleation. They rotate the chambers for 1 minute at 60 rotates per minute. This step started the cavitation activity. The large fluorescent molecules of dextran were taken by some cells, which show the permeabilization-like sonoporation of cells. Cell lysis was observed, and it kept increasing with the exposure. After the cell lysis, for the DNA transfection, scientists add 20μg/mL luciferase, which is an enzyme reporter plasmid, to the suspension during exposure. They performed the assays to check the proliferation ability and the luciferase gene expression, which show fluorescence. The cell proliferation was reduced, but cells showed higher luciferase production in the serum-provided medium than in the serum-free medium. The Chinese hamster ovary cells showed the same proliferation and transfection at the log or stationary phase. This effect only disappears when the Albunex is excluded. So the sonoporation procedure gives plasmid transfection with short-term gene expression.   

DNA In-Vitro Transfection into Mammalian Cultured Cells  

It is an in-vitro transfection method. Researchers used calcium phosphate and DEAE dextran reagent and incorporated them into the chemical procedure. It was done for the first time in history and successfully transferred nucleic acid into mammalian cultured cells. It was observed that plasmid DNA could efficiently be transfected into the mammalian cells using the calcium phosphate and DEAE dextran method. At that time, the purification and propagation of DNA were easy. After the successful development of this experiment, it started to become familiar with the chemical methods and the reagents, but calcium phosphate is a widely used experiment.