Hi everyone,
I am currently trying to prepare samples for ChIP seq analysis but keep loosing all my DNA in the last purification step. I am using an antibody against a transcription factor and get good enrichment of targets (tested by qPCR). The only problem is I never seem to be able to get sufficient DNA back out off the qiagen column to test the concentration using the Qubit system. I have double checked that the DNA elutes from the protein A beads and if I do exactly the same process with input DNA (which I have diluted to the same concentration as my ChIP samples) I am able to easily purify the DNA using these columns. I have checked the pH of my samples (they are about pH 7.5 as recommended). The only thing I can think of is that the DNA is not being reverse crosslinked in my ChIP samples (I add 5M NaCl and heat overnight at 65C). I was wondering if anyone has had a similar experience or could give me any suggestions. It is slowly driving me nuts and any help will be very gratefully received.
Thanks Sally
I am currently trying to prepare samples for ChIP seq analysis but keep loosing all my DNA in the last purification step. I am using an antibody against a transcription factor and get good enrichment of targets (tested by qPCR). The only problem is I never seem to be able to get sufficient DNA back out off the qiagen column to test the concentration using the Qubit system. I have double checked that the DNA elutes from the protein A beads and if I do exactly the same process with input DNA (which I have diluted to the same concentration as my ChIP samples) I am able to easily purify the DNA using these columns. I have checked the pH of my samples (they are about pH 7.5 as recommended). The only thing I can think of is that the DNA is not being reverse crosslinked in my ChIP samples (I add 5M NaCl and heat overnight at 65C). I was wondering if anyone has had a similar experience or could give me any suggestions. It is slowly driving me nuts and any help will be very gratefully received.
Thanks Sally
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