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.
... ...
URL: Troubleshooting DNA agarose gel electrophoresis
Archived page
Last update 13-Jun-2001, Rating Fair of 13 votes.
|
Write your comment
|
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
Rating: n/a
Reply
|
|
|
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
Rating: n/a
Reply
|
|
|
Redid expt. re-ran gel the program for measuring concentration showed no contamination from RNA,Protein or outside sources. same result. >.<
Rating: n/a
Reply
|
|
|
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 >.<
Rating: n/a
Reply
|
|
|
see actually how do you know wether a band is due to plasmidDNA or rna
Rating: Excellent!
Reply
|
|
|
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
Rating: Excellent!
Reply
|
|
|
The gel shrivels up a bit at the well end.
Rating: n/a
Reply
|
|
|
why does DNA sample along with loading dye not settle in the well while loading?
Rating: n/a
Reply
|
|
|
why gapdh primers gives different bands during agarose gel electrophoresis
Rating: n/a
Reply
|
|
|
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...)
Rating: Fair
Reply
|
|
|
If the DNA doesn't migrate, check the power supply and buffer. It's most likely one of them got problem.
Rating: Very Good
Reply
|
|
|
what do you do if the DNA remains in the wells and does not run?
Rating: n/a
Reply
|
|
|
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?
Rating: Good
Reply
|
|
|
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
Rating: Good
Reply
|
|
|
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...
Rating: Good
Reply
|
|
|
what do you do if the DNA remains in the wells and does not run?
Rating: Good
Reply
|
|
Related resource
Single Cell Gel Electrophoresis (SCGE) Comet Assay
method of choice to identify DNA bending, kinking or any other deformation?
Whats going on with phenol?
Separation of specific DNA fragment
Protocol: DIG Glycan Differentiation Kit from Roche
DNA RNA Protein Tri isolation method (MRC)
gDNA isolation from mouse lymphocytes
EtOH ppt of DNA, whats wrong with this strategy?
|
