How is isopropyl alcohol useful in dna extractions

Thanks for this clear explanation. It helps a lot the students who discover the beautiful world of molecular biology! Facebook Twitter LinkedIn More. Written by Dr Nick Oswald. Claire on February 2, at am. Mirza on September 20, at am.

Thanks from Indonesia. Share via. Copy Link. Powered by Social Snap. Copy link. Air-dry the pellet for 5—20 min depending on the size of the pellet. Redissolve the DNA in a suitable buffer. How can I precipitate genomic DNA using isopropanol? FAQ ID Alcohol precipitation is commonly used for concentrating, desalting, and recovering nucleic acids.

To identify bacteria and viruses in an environmental sample, diagnose disease pathologies, or examine a biological sample for forensic purposes, the DNA can be removed from the nucleus of a cell and its proteins can be separated by electrophoresis.

Salt, isopropanol and ethanol are commonly used to precipitate DNA. The DNA extraction process begins with the mechanical separation of the nuclear contents from the rest of the cell, which is carried out by sonication, agitation and the addition of SDS detergents. To further break down cell components and then draw off the DNA associated proteins, researchers typically add ammonium, sodium acetate or similar salts during this stage of the procedure.

Since DNA is insoluble in ethanol and isopropanol, the addition of alcohol, followed by centrifugation, will cause the DNA proteins to come out of the solution. When DNA concentration in the sample is heavy, the addition of ethanol will cause a white precipitate to form immediately. If the DNA concentration in the sample is low, isopropanol may work better than ethanol to precipitate the available proteins. In addition, isopropanol is often used for precipitating DNA from large volumes as less alcohol is used see protocols below.

The ethanol and isopropanol can also wash away the remaining salt residue. After being washed in alcohol and subjected to a centrifuge, the precipitated DNA protein will form a pellet, which can be washed in alcohol again, dried, and re-suspended in a Tris or TE buffer.

Be careful not to overdry the sample, since this can denature the DNA; just leave the washed pellet on the lab table for a few minutes.