What was possibly wrong in my gel electrophoresis when I didn't see bands of DNA ladder, and genomic DNA sample on gel ? I could see bands of genomic PCR and RNA solution.enter image description here


Thank you all of guys for sharing your opinions. From some opinions, I found out the possible error that my genomic DNA didn't show up because it was not pure (I forgot the detail that our group used a sample of DNA which was extracted from a previous lab and we didn't obtain an expected ratio for the purity of DNA. Then, we also used the impure DNA sample to do PCR, and finally used the amplified DNA for gel electrophoresis lab). However, the reason for DNA ladder didn't show up I'm not sure. I just can suppose that my groupmate who handled with DNA ladder solution possibly contaminated it.

  • $\begingroup$ Can you tell us how you are visualizing the gel? The answer probably revolves around the way the gel and samples are prepped and imaged. $\endgroup$
    – Chastain
    Commented Nov 19, 2014 at 18:03
  • $\begingroup$ Perhaps your ladder has gone off! $\endgroup$ Commented Nov 19, 2014 at 18:48
  • 3
    $\begingroup$ Can you show an image? $\endgroup$
    – Chris
    Commented Nov 19, 2014 at 19:19
  • 1
    $\begingroup$ This picture is still not very clear. Don't you have a gel-doc in your lab? $\endgroup$
    Commented Nov 20, 2014 at 5:14
  • 3
    $\begingroup$ This question appears to be off-topic because it does not provide sufficient details required for a precise answer. Questions related to experiment troubleshooting should provide all necessary details about the experiment. $\endgroup$
    Commented Nov 21, 2014 at 17:55

1 Answer 1


Possibly You don't mix ladder containing microtube by Sampler. You should slowly Fill and emptying Sampler for several times when pick it for use, mix it well, but do it without creating a bubble.one more thing, check your ladder by "NanoDrop"

  • $\begingroup$ Do you think a sample of DNA which was not pure can influence to my result? Could you explain more why creating a bubble can cause a bad result, please? $\endgroup$
    – Kim
    Commented Nov 20, 2014 at 10:12
  • $\begingroup$ @Kim well, there are number of reason in each part of protocols lead to make bad results so each idea that friends have mentioned are also considerable and having Inappropriate sample is one of them. creating a bubble can cause a bad result because When you use small amount of Ladder so if bubble will be taken as samples, your measurements will be very low and inefficient. I propose check process of preparation of Ladder work. $\endgroup$
    – M007
    Commented Nov 20, 2014 at 13:08
  • $\begingroup$ @Kim can you please check your ladder by nanodrup?and compare result for each of DNA and RNA and proteins? $\endgroup$
    – M007
    Commented Nov 21, 2014 at 8:10
  • $\begingroup$ I'm afraid I can't. You know, we just could follow a protocol which was given to us. I was doing the experiment for a class at college level. What is nanodrup? $\endgroup$
    – Kim
    Commented Nov 21, 2014 at 23:49
  • $\begingroup$ @Kim For more information about nanodrup please visit this and this links $\endgroup$
    – M007
    Commented Nov 22, 2014 at 7:01

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