I am using CTAB method for isolating genomic DNA from Arabidopsis leaves. After dissolving the DNA in 0.1X TE buffer, it is visualized in EtBr agarose gel. The DNA showing 5-7 different bands like a DNA marker. Can anyone tell the reason for this?
Without seeing the picture of the gel I can be sure but as you described it it sounds RNA to me. You could try a RNase H treatment with a little sample of your DNA (you could find the details in many protocols for DNA extraction), and check it again in the agarose gel.
Thanks for the explanation. I am attaching here the gel image. First well is 100bp ladder. Second and third wells are DNA samples
Your genomic DNA is the top band.
Simply perform an RNAse A treatment and the lower RNA bands will disappear.
Should be check the buffer pH. If less then pH 8.0, the RNA contamination will more. Before the extraction the leaves were surface sterilized with 70% ethanol and the sterile water.
I agree with the above. You certainly have a high amount of RNA in your samples, which can be removed by RNAse A treatment. Only the weaker top band is genomic DNA. This example also shows that you indeed can check RNA quality and amount using standard agarose gels (even when not working RNAse free).
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