Exogenous DNA is DNA originating outside the organism of concern or study. Exogenous DNA can be found naturally in the form of partially degraded fragments left over from dead cells. These DNA fragments may then become integrated into the chromosomes of nearby bacterial cells to undergo mutagenesis. This process of altering bacteria is known as transformation. Bacteria may also undergo artificial transformation through chemical and biological processes. The introduction of exogenous DNA into eukaryotic cells is known as transfection. Exogenous DNA can also be artificially inserted into the genome, which revolutionized the process of genetic modification in animals. By microinjecting an artificial transgene into the nucleus of an animal embryo, the exogenous DNA is allowed to merge the cell's existing DNA to create a genetically modified, transgenic animal. The creation of transgenic animals also leads into the study of altering sperm cells with exogenous DNA.
Transfection in the context of Selectable marker
A selectable marker is a gene introduced into cells, especially bacteria or cells in culture, which confers one or more traits suitable for artificial selection. They are a type of reporter gene used in laboratory microbiology, molecular biology, and genetic engineering to indicate the success of a transfection or transformation or other procedure meant to introduce foreign DNA into a cell. Selectable markers are often antibiotic resistance genes: bacteria subjected to a procedure by which exogenous DNA containing an antibiotic resistance gene (usually alongside other genes of interest) has been introduced are grown on a medium containing an antibiotic, such that only those bacterial cells which have successfully taken up and expressed the introduced genetic material, including the gene which confers antibiotic resistance, can survive and produce colonies. The genes encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline, kanamycin, etc., are all widely used as selectable markers for molecular cloning and other genetic engineering techniques in E. coli.
View the full Wikipedia page for Selectable markerTransfection in the context of HEK 293
Human embryonic kidney 293 cells, also often referred to as HEK 293, HEK-293, 293 cells, are an immortalised cell line derived from HEK cells isolated from a female fetus in the 1970s.
The HEK 293 cell line has been widely used in research for decades due to its reliable and fast growth and propensity for transfection. The cell line is used by the biotechnology industry to produce therapeutic proteins and viruses for gene therapy as well as safety testing for a vast array of chemicals.
View the full Wikipedia page for HEK 293