DNA (deoxyribonucleic acid) is a complex molecule that contains the genetic material of a cell. It defines the structure and the functions of a living organism. DNA is also responsible for heredity.
DNA is composed of a series of nucleotides linked together. These nucleotides are basically made of a nitrogenous base, a molecule of sugar (deoxyribose), and a phosphate group. The sequence of nucleotides in the DNA molecule determines the hereditary traits of a cell. Nucleotides are packed to fit inside the cell. DNA takes the shape of a double helix, which, in addition to the DNA molecule contains bound proteins. DNA double helix is enclosed inside a cell membrane in case the cell doesn’t have a nucleus like in prokaryotes, and inside the nuclear membrane in cells with nuclei like in eukaryotes.
DNA has been the target of a lot of research. Investigation of the DNA structure and sequence in relation to diseases helped in finding out the molecular basis and cure for various diseases. DNA study also allowed the production of many vaccines, hormones, and enzymes. DNA study was also very beneficial in the forensic/medico-legal entities. To study DNA it must be extracted out of the cell, Hence; the DNA extraction technique is widely used in research labs.
The isolation of the DNA is done in stages:
- Cell dissolution: In this stage, the cell and the nucleus are broken to extract a DNA sample using a lysis buffer.
- Precipitation: In this stage, proteins and impurities are removed from the sample.
- Purification: This stage involves isolating the DNA completely from the other substances, for a final eluted pure DNA sample preserved in a buffer.