M. luteus can be found in many places such as the human skin, water, dust, and soil. Micrococcus is generally thought of as harmless bacterium, but there have been rare cases of Micrococcus infections in people with compromised immune systems, as occurs with HIV patients.
Therefore when used in gel electrophoresis, markers effectively provide a logarithmic scale by which to estimate the size of the other fragments (providing the fragment sizes of the marker are known). Protein, DNA, and RNA markers with pre-determined fragment sizes and concentrations are commercially available.
Gel Electrophoresis is used to separate DNA fragments by their sizes and charges. It makes it possible to identify the differences and similarities between different plants and animals. Although there are some different types of Gel Electrophoresis such as Capillary and Agarose, this is how the general technology works: