What is transfection? what are the two subtypes? and what are the three ways of transfection?

Transfection is the process of introducing foreign nucleic acids into eukaryotic cells to genetically modify the cell. transfection can be stable, meaning that the foreign nucleic acids are integrated in the host's genome or remain present in the host cell as an extra-chromosomal element. this means that the transgene remains expressed as the cell replicates. transfection can also be transient, meaning that the foreign nucleic acids are present in the host cell as a plasmid or as oligonucleotides. after a couple of cell replications, the transgene will be lost. the three ways of transfection are viral transfection, physical transfection and chemical transfection.