the Salt, Alcohol and Salt?
do it yourself DNA
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ddsolis
- Posts: 2
- Joined: Tue Jan 22, 2008 2:12 pm
- Occupation: student
- Project Question: What does each ingredient do in the do it yourself dna...Salt, Rubbing Alcohol and Dawn detergent?
- Project Due Date: 1/23/08
- Project Status: I am finished with my experiment and analyzing the data
do it yourself DNA
What do the different ingredients do in the do it yourself DNA PROJECT
the Salt, Alcohol and Salt?
the Salt, Alcohol and Salt?
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barretttomlinson
- Former Expert
- Posts: 932
- Joined: Wed Oct 03, 2007 12:24 am
Re: do it yourself DNA
Hi!
To answer your question I found the following quote in this reference:
http://www.accessexcellence.org/AE/AEC/ ... tions.html
“There are two to three basic steps in DNA extraction. The cell must be lysed (broken open) to release the nucleus. The nucleus (if present) must also be opened to release the DNA. At this point the DNA must be protected from enzymes that will degrade it, causing shearing. Once the DNA is released, it must then be precipitated in alcohol.
In order for the cell to be lysed, the lipid walls must be broken down. The detergent and salt solutions accomplish this. Cell walls, cell membranes, and nuclear membranes are also broken down by the action of the blender. In all but one protocol I eliminated the use of heat. Some references state that a temperature of 60oC is necessary to denature the DNAase enzymes that cause shearing in DNA while DNA is denatured about 80oC. Other references state that DNA can denature at 60oC. From all the experiments I ran (except for the wheat germ protocol), I had sheared DNA when I used heat. Heat may destroy the enzymes as well as the DNA. However keeping the solutions cool seems to slow the enzyme action. The prep solution uses epsom salts and buffered aspirin to further deactivate the enzymes that degrade DNA when released and stabilize the DNA (acid vs. base). Sodium bicarbonate (baking soda) also is used to buffer the solution. The meat tenderizer has papain, an enzyme that helps clean the protein from the DNA that can contaminate it. Papaya juice and pineapple juice also contains this enzyme. Finally, the ethanol is used to precipitate the DNA. In water, DNA is soluble. When it is in ethanol, it uncoils and precipitates leaving behind the other cell components that are not soluble in ethanol.”
This is a very practical experiment. Hope you enjoy doing it!
Best regards,
Barrett Tomlinson
To answer your question I found the following quote in this reference:
http://www.accessexcellence.org/AE/AEC/ ... tions.html
“There are two to three basic steps in DNA extraction. The cell must be lysed (broken open) to release the nucleus. The nucleus (if present) must also be opened to release the DNA. At this point the DNA must be protected from enzymes that will degrade it, causing shearing. Once the DNA is released, it must then be precipitated in alcohol.
In order for the cell to be lysed, the lipid walls must be broken down. The detergent and salt solutions accomplish this. Cell walls, cell membranes, and nuclear membranes are also broken down by the action of the blender. In all but one protocol I eliminated the use of heat. Some references state that a temperature of 60oC is necessary to denature the DNAase enzymes that cause shearing in DNA while DNA is denatured about 80oC. Other references state that DNA can denature at 60oC. From all the experiments I ran (except for the wheat germ protocol), I had sheared DNA when I used heat. Heat may destroy the enzymes as well as the DNA. However keeping the solutions cool seems to slow the enzyme action. The prep solution uses epsom salts and buffered aspirin to further deactivate the enzymes that degrade DNA when released and stabilize the DNA (acid vs. base). Sodium bicarbonate (baking soda) also is used to buffer the solution. The meat tenderizer has papain, an enzyme that helps clean the protein from the DNA that can contaminate it. Papaya juice and pineapple juice also contains this enzyme. Finally, the ethanol is used to precipitate the DNA. In water, DNA is soluble. When it is in ethanol, it uncoils and precipitates leaving behind the other cell components that are not soluble in ethanol.”
This is a very practical experiment. Hope you enjoy doing it!
Best regards,
Barrett Tomlinson