Ethanol vs Isopropanol for DNA precipitation - (Sep/23/2004 )
the dna precipitation will be better using the alcohol that be more soluble in water
If you want instant precipitation without using salt then use 9 volumes of butanol. I use it all the time for cleaning up ligation reactions for electroporation.
Daniel
DNA sequencing reagents & software
I guess this is why at most protocols you precipitate the DNA with isopropanol (witch will precipitate faster but a litle dressing with salt), and than make a wash with ethanol 70%, witch will clean some of the salt...
The problem with isopropanol is it can put down more salts and "gunk" than ethanol - the advantage is you only need to use 0.6 vol
Hi,
...and (as mentioned in other threads) add a little bit glycogen. It helps a lot to precipitate DNA.
Hobglobin
As far as i know, the advantages of isopropanol precipitation over ethanol precipitation are
1. For the same amount of DNA, lesser voume of isopropanol is required.
2. Lesser salts precipitated.
3. Done at room temperature.
4. More effective in removing primers and fragments cut off during restriction digestion.
Normally I only use the Amersham kit (GFX PCR DNA gel band purif. kit) to purify DNA, e.g. PCR products, digested plasmids etc. You can purify the DNA from solutions and from the gel slice.
The concentration of the DNA is always satisfactory for simple cloning experiments. The main advantage is that:
It always works fine
Is fast - 15-17 min from gel slices; 5-7min from solutions.
Why do you prefer the precipitation with EtOH/Isoprop/Phen-Chlor ? What are the advantages of them in comparison to the kit? I have never used them, so I do not know them...
Probably the kit costs more than just a simple precipitation but it is really easy and fast to perform.
Hey, where are you people? 
Can you answer my question?
For me: the cost is indeed important, also with kits your less in control of what's happening, sometimes old buffers don't function as good, or the membranes on the columns aren't good anymore.
The concentration of the DNA is always satisfactory for simple cloning experiments. The main advantage is that:
It always works fine
Is fast - 15-17 min from gel slices; 5-7min from solutions.
Why do you prefer the precipitation with EtOH/Isoprop/Phen-Chlor ? What are the advantages of them in comparison to the kit? I have never used them, so I do not know them...
Probably the kit costs more than just a simple precipitation but it is really easy and fast to perform.
Well, some people prefers pp, they say it’s simple and recovered the same amount of DNA than using kits.
Personally, I prefer kits, of course it’s more expensive!! But at least in my experience, it’s much faster and I recovered more DNA than pp.
And in my experience, I get more DNA with QIAGEN kits compared to other kits like Promega.
And by the way… again, in my personal experience.. it’s cheaper using kits, because as I recover good amounts of DNA, I need less DNA and LESS ENZYME for digestions…
