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No bands appearing in DNA gel electrophoresis - (May/08/2012 )

Hello all,

So last month for my molecular biology class I had an issue. After quantifying the DNA and finding it to be an adequate amount for PCR, we ran the reaction (sorry I can't remember the exact amount). Afterwards, in order to confirm our product, we ran it in a gel at 120 volts for 30 minutes. The amount of ethidium bromide used was 1 ul in 50ml of 1x tae mixed with 0.75 grams of agarose. The problem was that after running the gel we were able to see the ladder but not the samples.

I would also like it, for a research project I'm doing that investigates this problem, if somebody could provide me some links to some research articles that pertain to this issue. Additionally, I was also wondering if anybody else has experienced this problem before and what they have done about it.

Thank you very much


So you loaded some of your PCR sample into a gel and saw no band?

There are two places where something could have gone wrong- your PCR failed, or your gel loading. Can you think of some ways this could have happened?

As this is a homework question, I can't give you anymore than that without you first contributing some ideas as to why you think this might have happened and what could have gone wrong.