Transfection is a technique that’s widely used to transfer foreign nucleic acids into eukaryotic cells for the purpose of altering the genetic content of the host cells and ultimately changing the expression of desired genes in these cells. Some of the more significant applications of transfection include: 

• Production of stable cell lines that are very useful for large scale production of recombinant proteins that have important applications in therapeutics 
• As a basis for gene therapy to treat a wide range of diseases including but not limited to hemophilia, sickle cell anemia, Duchenne’s muscular dystrophy, and beta thalassemia 
• As an analytical tool for the purpose of studying protein or gene expression in different types of cells
• Production of DNA vaccines that stimulate the generation of adaptive immunity
• For gene silencing using RNAi molecules 
• For stem cell programming and differentiation