Ethanol Precipitation - No DNA!!! (Oct/24/2005 )
Hello everyone. I ran into problems with precipitating my DNA. I did the ethanol precipitation, but when I went to run the DNA on the gel electrophoresis, no DNA! Can anybody please tell me why this happened?
what was the solution on wich you did your ethanol precip?
For this, you should use at least 2.5 volume of ethanol 100% and it's better to add 1/10 volume of Na Acetate 3M ph5.5.
Did you see a pellet? How much DNA were you precipitating? Was it genomic or plasmid?
Yes, I did see a pellet. After the drying of both of my tubes, I did see DNA at the bottom. I resuspended the DNA in 15uL of distilled water. It is plasmid DNA that I am working with. With the ethanol precipitation, I added 150uL of NaAc and 1mL of 100% cold ethanol. I had about 500uL of DNA.
I should make a note to add in. I did see DNA at the bottom of my tube, but when I did the gel electrophoresis, no DNA showed up in the gel, only my markers showed up.
Maybe you should try to measure your DNA concentration on a spec. and see how much you actually recovered.
The white pellet that you see at the bottom of your tube may not always DNA, could be protein as well.
So the best way is quantitate you DNA using UV spectrophotometer and check for purity as well.
Could you please descript you protocol in greater detail and type of sample that you use? Somebody might be able to improve your protocol.