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multiple bands on genomic dna agarose electrophoresis

asked by by on

hello, i have done dna extraction from plant leaves by CTAB method, when i carry AGE of this sample i get-1. one band just below the well,
2.and two other bands at about half distance of the run. 3. also one smear below the dye
when treated with RNaseA,all these bands disappear
only the largest one remain, but as 260:280 ratio is 1.72, it may not RNA, then what are these bands? Is it chlorophyll DNA?
Please help
Thank you

Have an answer?

3 answers

  1. from on

    As far as I know..

    The smear at the end is because of RNA in the sample.

    The rest of the bands may be due to excessive shearing of DNA in the sample.

    About the chlorophyll DNA I am not sure.

  2. from on

    The smear indicates impurities and shearing of DNA due to harsh treatments in the extraction procedure such as excessive vortexing and leaving any step for longer periods than suggested. Sticking to the protocol is very crucial. If you have large number of samples to process time delay is unavoidable. In such case just attempt extraction in small batches.
    Satya Maddi

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