Missing Dye Front
Partial dye front – example 1
After doing so much work getting the gel set up,
it is a shame to be late taking it down. Relative
mobilities cannot be determined with accuracy if
the dye front is partially off of the gel.
In this case the gel was internally calibrated
- that is, molecular weight standards were included
on the gel. An arbitrary reference point can be
used for setting up the standard curve, since the
lanes were quite even.
No dye front – example 2
This one was allowed to run until the dye front
completely ran off. Since the lanes are somewhat
distorted, relative mobility measurement will be
compromised. With an intact dye front, lanes could
be compared even if the gel was distorted or of
different height on one side or the other. Relative migration
is the same for a gel of uniform composition, no
matter what the actual height of the resolving
gel.
No dye front – example 3
The curvature of this gel suggests that the spacers
on the sides were a bit loose, causing a field
effect near the edges (a 'frowning' gel). It will
be difficult to get accurate relative mobility
measurements because the dye front was allowed
to run off. With an intact dye front as a reference
point, lanes could be compared with one another
despite the 'frown.'
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