1. Ethanol is costlier than isopropanol.
2. Again isopropanol is faster in precipitation of DNA accompanying salts too whereas ethanol needs time and salts are dissolved.
3. Isopropanol works at room temperature while ethanol requires freezing temperature.
4. The longer your incubation time at freezing temperature, the more the yield of DNA in case of ethanol,
5. Ethanol gives about 10 fold higher yield of DNA than that of isopropanol.So, if the time and costs are the factors, better to choose isopropanol. And if the quality and yield are the concern, ethanol is the best option.
@Md. Asaduzzaman Shismir Especially regarding the temperatures I recommend you take a look at Zeugin JA, Hartley JL (1985). Focus 7 (4): 1–2: http://www.lifetechnologies.com/content/dam/LifeTech/migration/en/filelibrary/pdf/focus.par.56415.file.dat/focus%20volume%207%20issue%204.pdf
It depends on the purpose. I'll suggest you to read about DNA extraction in a Molecular Biology Manual. the classical one is Sambrook...Best,
I agree with Maria. "Molecular cloning, a laboratory manual" (Sambrook J and Russel DW, eds.). Cold Spring Harbor Laboratory, New York, is a great resource.
Also, currently available, on the Cornell website is a pdf resource with lots of details about how ethanol precipitation works. They talk about the various salts that can be used and discuss isopropanol versus ethanol.
Our lab uses one of three salts where the concentrations are in the DNA solution prior to adding 2.2 to 2.5 volumes of 100% ethanol:
Na-Acetate, 0.3 M
NH4-Acetate, 2.1 M
NaCl, 0.2 M
Then the precipitation is often done at -20 C overnight and the DNA is pelleted down in a 4C centrifuge the next morning.
New England Biolabs
Olga De Castro
University of Naples Federico II
Shanghai Jiao Tong University
Russian Academy of Sciences
Kris Cahyo Mulyatno
Chow Wee Ming
Tunku Abdul Rahman College
National University of Malaysia
Birla Institute of Technology and Science Pilani