Biochemical Techniques for the Extraction of Escherichia Coli Genomic DNA

845 WordsJul 17, 20184 Pages
Modern biochemical study and analysis of nucleic acids have been heavily dominated by electrophoresis and polymerase chain reaction techniques, as the former allows for relatively inexpensive and accessible resolution and visualization of nucleic acids according to basic chemical properties such as molecular charge and weight, and the latter quickly increases the concentration of nucleic acids, normally found in cells in minute amounts, to a level easily analyzed by modern biochemical techniques. These two techniques are therefore currently indispensable in dealing with nucleic acids on a practical level, and are tools which should be present in every biologist’s kit. This study therefore attempts to elucidate the theoretical and…show more content…
While ample plant and animal samples can be easily obtained, for bacterial samples such as E. coli, they must be propagated first in culture in order to obtain the necessary amount of cells needed for the DNA extraction process. The extraction and purification of genomic DNA is essential as purified DNA serves as the starting point for the amplification of a gene within the DNA via the Polymerase Chain Reaction (PCR). First and foremost, cell lysis or cell disruption must be done to release the cell contents to expose the DNA within the organism, detergents, basic or high salt solutions will then be used for DNA purification by dissociating other biomolecules such as proteins and lipids. DNA will finally be isolated through the use of organic reagents and centrifugation to facilitate collection of the precipitated DNA. Prior to the experiment, materials to be used were sterilized to prevent contamination, which may later on affect the results as contaminants may react with the solutions to be used for the later procedures or even damage the DNA samples. Autoclaving or the use of pressurized steam was utilized to sterilize the materials as exposure to high temperatures normally causes damage to cytoplasmic membranes, breakdown of ribosomes, irreversible enzyme denaturation and DNA strand breakage of bacterial contaminants. Due to the ability of nucleic acids to store genetic information which will later on encode for necessary proteins, it is important to extract
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