DNA "refusing" to be run in agarose gel

Jillian Johnston johnstoj at acs2.acs.ucalgary.ca
Fri Aug 25 12:24:20 EST 1995

If you continue to have troubles keeping the sample in the well,
a trick we use here is to load the gel 'dry'.  We use Pharmacia
gel boxes and if you place the gel in them and fill up the buffer
chamber to the top og the gel but not over the gel the wellsa
stay dry. Load the smaples and run the gel for a minute or two
until the dye has entered the gel and then fill the box as full
as you want with buffer.  Don't wait too long or you get a bit of
a distortion like a pointer.
Good luck!
Ketil Thorstensen (ketilt at dmf.unit.no) wrote:
: Honored contributors to the molbio.methds-reagnts!

: I have a peculiar problem with persuading some of my DNA samples to run in 
: agarose gels.

: When loading DNA samples on agarose gels I have on several occasions observed 
: a strange (to me) phenomenon: after application of a sample into a well a 
: streak of the sample may follow the pipette tip upon withdrawal. When the 
: sample in this way comes in contact with the buffer surface, the sample very 
: rapidly spreads out to cover the entire surface. During this process most of 
: the sample in the well is "sucked" out.
: There is no recognizable pattern as to what sample this may happen with. It 
: is, however, frustrating when precious samples are lost (the last one was a 
: 1.9 kb DNA probe)  :í-(
: Could anyone enlighten me as to what I am observing, and how to prevent 
: this from happening again?

: Thank you very much,

: Ketil Thorstensen, Ph.D.
: Dept. Clinical Chemistry
: University Hospital
: Trondheim, Norway

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