Hi, I'm a 2nd year student in biomedical science and currently writing a lab report for which I need to measure DNA band sizes on electrophoresis. The lane for PCR amplified DNA has a very thick bright band that i am not sure how to measure or how to interpret. This is the results given by our professor, not the ones we generated in our practical class so I don't think it's because the wells weren't loaded properly or some error like that (unless they're trying to trick us).
Sorry if it's a stupid question my brain is very tired right now.
It's lane 5 on the image
I would say that the very faint band in the previous lane is spillover from the strong signal and you should use this to determine size against the size ladder. Alternatively either use the middle of the strong band or run a new gel with one tenth the amount of loaded dna
Is this an exam question or can you actually do the experiment? If the former, the faint band on lane 4 looks like the overflow of lane 5, and would give you the correct size. If the latter, dilute your PCR product 5 times and run it again
This image is obviously spliced together from several images, I imagine your professor chose them to represent a particular result.
They probably want you to compare the bands to the ladder to approximate the product sizes. Compare that to the sizes you expected & then interpret the results.
For the super thick band, estimate from the middle of the band & call it good enough.
Since the band is very heavy and contains multiple sub bands....
Try to decrease the conc of Dna in next pcr.....
I recommend that you check the attached file that is related to the errors of electrophoresis DNA
https://www.researchgate.net/profile/Niloufar-Mohammadkhani/post/agarose_gel_electrophoresis_troubleshooting/attachment/5b98bcdfcfe4a76455f2903d/AS%3A669935500017675%401536736478993/download/DNA_Troubleshooting.pdf
This is because the amount of stain in a band is approximately proportional to the amount of DNA in that band. Accordingly, a dark, thick band indicates a highly abundant DNA molecule in the sample. A faint, thin band indicates that a relatively small amount of that DNA molecule is present in the sample
Hi Anamaria,
Our Phoretix 1D software will be able to give you quick measurements to quantify the size of your DNA bands relative to your ladder.
You can get a free trial of the software here: https://totallab.com/products/phoretix-1d/
and view some tutorial videos of how to use the software on our YouTube channel here: https://www.youtube.com/playlist?list=PL3hWcOC8KbJez_KqCvpHtT5T6c6NjiAnS
Dcrease the cycle of pcr less than 30 cycle not more make it 29 cycle
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