Question

The purified DNA ultimately precipitates out after the addition of chilled ethanol. This DNA that separates out can be removed by
A. Electrophoresis
B. Downstream processing
C. PCR
D. Spooling

Answer 1

DNA is also known as deoxyribonucleic acid. It is regarded as the genetic material. A person’s body has trillions of cells and each contains a similar type of DNA. The information retained in DNA is stored as codes and it is made up of four types of chemical bases: adenine, thymine, guanine and cytosine.

Complete answer:
There are three steps for DNA separation; lysis, precipitation and purification.
In lysis, the cell, as well as the nucleus, is opened so that the DNA can be released inside and it is done in two ways. Firstly, the mechanical disruption opens the cell and this can be done with a small blender or mortar and pestle or by cutting the tissue in smaller fragments. Now, the DNA is exposed but it is mixed with the cell parts. So in precipitation, the DNA is freed from the other cell parts. Firstly, the sodium ions are added that neutralize the negative charge on DNA and makes it less soluble in water. After that, the alcohol is added that causes the DNA to separate or precipitate as it doesn’t dissolve in alcohol. If any cellular parts are stuck to DNA, they are removed by adding more alcohol. The purified DNA separates after the addition of alcohol or ethanol and we have a collection of fine threads which can be spooned out with a glass rod and this process is known as DNA spooling.
Hence, the correct answer is option D.

Additional information: DNA was discovered by Friedrich Miescher in 1869. Before this scientists believed that DNA was not the genetic material and that proteins stored the genetic information in all living organisms up to 1943.

Note: The DNA is about six feet long when unwinded. A human body is made up of 100 trillion cells and if the DNA of all 100 trillion cells is unwinded, we can go to the sun and come back to earth more than 500 times.