DNA isolation

News 10/22/2019

How does the first stage of any molecular genetic research work?

DNA is a macromolecule that stores information about the structure of various proteins, cells and tissues in the form of a genetic code and ensures the transmission of this information from generation to generation. For the first time, the Swiss doctor Friedrich Miescher isolated DNA in 1869.

DNA is found in all cells of the human body that have nuclei. DNA can be extracted from scraping buccal (buccal) epithelium, blood lymphocytes, and biopsy material. Small amounts of DNA are present in the blood plasma. During pregnancy, fetal DNA can be detected in the mother's blood.

The isolation of DNA from biological material is the first stage of any molecular genetic study. In the laboratory of the Center for Personalized Medicine of the MCSC, this stage is automated and performed by a robot.

The process of DNA isolation can be divided into several stages:

• It is necessary to destroy the cell membranes so that the DNA comes out in solution. To do this, we use a lysing buffer containing surfactants (surfactants) and a special enzyme – proteinase K. SURFACTANTS destroy cell membranes, proteinase cleaves DNA-binding proteins, and the buffer component maintains the pH at the optimal level for DNA. However, along with the DNA in the solution are other components of cells-proteins, "fragments" of cell membranes, sugars.
• It is necessary to clean the DNA from impurities. By means of centrifugation, we filter our solution through a silicate membrane on special columns. The DNA reversibly binds to the membrane, while the other organic components of the cell pass through it. At this stage, we use the chemical properties of DNA, its ability to dissolve poorly in alcohols and well in water.
• The membrane with the bound DNA is washed several times with isopropyl and / or ethyl alcohol to finally get rid of impurities.
• Apply an elution buffer to the column membrane. Elution is the extraction of a substance from a solid carrier by leaching.

The isolated and purified DNA can be stored in a freezer at -20°C for several years.

#Переведено YandexTranslate