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DNA agarose gel electrophoresis



DNA agarose gel electrophoresis

If you see faint or no bands on the gel:

There was insufficient quantity or concentration of DNA loaded on the gel. Increase the amount of DNA, but don't exceed 50 ng/band.

The DNA was degraded. Avoid nuclease contamination.

The DNA was electrophoresed off the gel. Electrophorese the gel for less time, use a lower voltage, or use a higher percent gel.
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URL: Troubleshooting DNA agarose gel electrophoresis

Last update 13-Jun-2001, Rating of 16 votes.

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By orline on 21-Nov-2008
Si l 'ADN reste dans les puits,je pourrai chercher à le digérer puis à effectuer des tests de vérification de sa présence dans le puits et recommencer une nouvelle expérience.
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By viralkumar on 19-Nov-2008
i am doing currenlty whole genome DNA isolation from cotton varieties since long but i am getting searing of DNA band however the DNA purity 1.89. please help out me from this problem.
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By john on 23-Sep-2008
i have problem with the running of agarose gel. i extracting the bacterial gen by simply heating method or insta gene latex method. but there is no visual band i.e seperation or florence of DNA in the gel, what should i do for the good result? i am making diluting 1:1, 1:2, 1:4 sample of loading
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By Adilla on 02-Jul-2008
I dont know if someone can help me, I am trying to verify the quality of a cDNA that was kept in the fridge for 1 year but I got a very weak band and a long smear down in the gel... but i dont know if it is good enough for real time pcr or if I should take samples and extract from RNA.... ideas please
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By Adilla on 02-Jul-2008
I dont know if someone can help me, I am trying to verify the quality of a cDNA that was kept in the fridge for 1 year but I got a very weak band and a long smear down in the gel... but i dont know if it is good enough for real time pcr or if I should take samples and extract from RNA.... ideas please
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By PJ on 05-Mar-2008
Redid expt. re-ran gel the program for measuring concentration showed no contamination from RNA,Protein or outside sources. same result. >.<
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By pjww on 04-Mar-2008
I ran a gel earlier today with plasmids, all of them measured a high concentration but nothing showed up on the gel. i checked the gel, buffer, and voltmeter and they were fine. not sure what to do. help >.<
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By m ganapathi on 03-Jan-2008
see actually how do you know wether a band is due to plasmidDNA or rna
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By juned on 20-Nov-2007
i have perform an isolation,purification and anlysing plasmid and genomic dna of e.coli containning puc18 and restriction endonuclease followed by gel electrophoresis
the result igot is only genomic dna and that is sheared and has a tail with a rna smearso sugest me the possible causes of not getting plasmid dna
and why there is rna smear and tailing of genomic dna
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By anne stephens on 14-Aug-2007
The gel shrivels up a bit at the well end.
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By Renu on 11-Jul-2007
why does DNA sample along with loading dye not settle in the well while loading?
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By binu k a on 13-Jun-2007
why gapdh primers gives different bands during agarose gel electrophoresis
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By Innuendo on 11-Jun-2007
In my agarose-geles (1%) some of the bands of my DNA-preparations migrate to the opposite pole, while other bands migrate correctly (to +)... what is going on?!
(We use 1xTAE as running buffer...)
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By electrophoresis on 09-Mar-2007
If the DNA doesn't migrate, check the power supply and buffer. It's most likely one of them got problem.
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By rupali shinde on 01-Jun-2006
what do you do if the DNA remains in the wells and does not run?
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By Cherie on 18-Mar-2005
Sounds like you have your insert but your enzyme isn't cutting. I'd check your 10x buffer that goes with your enzyme and increase the amount of incubation time to at least 2 hours. Do you also show nicked and supercoiled bands with your 9kb band?
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By ray pandy on 21-Sep-2002
cloneshould have a 5kb insert in a 4kb vector. However only a weak band at 9kb observed.Major band is a 2kb one on 1% agarose. gel isolated 9kb band, transformed and regrew up cultures...same problem...restriction digests do not cut 2kb band but does cut 9kb band. sequencing indicates presence of full length insert...HELP
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By jonnyr9 on 23-Jul-2002
Try removing salt or sugars from the sample...eg. reprecipitate and wash with large volumes of 70% ethanol 2 or 3 times (eg. 1mL), breaking up the pellet very well....



Check the pH of the running buffer both conc stock and working buffer in your gel tank...sometimes people make it up wrong....



Don't let the gel try out once you have poured it....pour it at about 60 Celsius, then leave it to gel for 30 minutes, after which time submerge it in running buffer. Otherwise all parts exposed to air will dry faster than the inside of the gel, forming a 'rind' (like orange peel)...this dry rind will stop things making it into the gel...



Jon



PS. Check out this site: http://www.molbiol.net

for more molecular biology answers...
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By zhry4 on 22-Feb-2002
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By sameer nath on 13-Jun-2001
what do you do if the DNA remains in the wells and does not run?
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