Biotechnology Archive
Ultraviolet light absorption is a general method for detecting DNA, but does not distinguish between different DNA molecules. DNA can also be detected with radioactive isotopes During replication, radioactive precursors such as 32P in the form of a phosphate group …
The ability to isolate, separate, and visualize DNA fragments would be useless unless some method was available to cut the DNA into fragments of different sizes. In fact, naturally occurring restriction enzymes or restriction endonucleases are the key to making …
Gel electrophoresis followed by staining with ethidium bromide is used to separate DNA fragments by size . The gel of gel electrophoresis consists of agarose , a polysaccharide extracted from seaweed that behaves like gelatin. Agarose is a powder that …
Basic to all biotechnology research is the ability to manipulate DNA. First and foremost for recombinant DNA work, researchers need a method to isolate DNA from different organisms. Isolating DNA from bacteria is the easiest procedure because bacterial cells have …
It is also a mode of bacterial gene transfer, which is mediated by viruses. It is a frequent mode of horizontal gene transfer in nature. Indeed evidence suggests that the number of genes moved by marine viruses from one host cell …
It is another way, DNA can move between bacteria is through transformation, discovered by Fred Griffith in 1928. Transformation is the uptake by a cell of DNA, either a plasmid or a fragment of linear DNA, from the surroundings and …
Conjugation, the transfer of DNA by direct cell-to-cell contact, depends on the presence of a conjugative plasmid. Plasmids are small, double-stranded DNA molecules that can exist independently of host chromosomes. They have their own replication origins, replicate autonomously, and are …