I wouldn't expect the gel to polymerize at a different rate just where the
"frown" appears. Not for TWO gels cast separetely. Besides...why just in the
middle and nowhere else.
On checking with other folks in the lab turns out that it isn't a new
phenomenon but has been observed by others. Of course, no one knows why
exactly though - there are speculations.
It is a quite annoying at the end of the run to find that the separation is
going to be messed looking at the "frowns".
K
