[2–5]) uses different fluorescent staining to label the analyte
and a grid of marker proteins on one gel in an effort to relate
the former to the latter and thus generate much more reproducible protein spot coordinates. The grid is formed with an
adapted 1D-PAGE approach (for detailed explanation of the
procedure see[2,4]). Briefly, in vertical (v)CoFGE, marker wells
are casted on top of the pI-strip carrying the sample and
filled with a defined mixture of standard proteins. Analyte
and marker are separated at the same time during GE in that
way. Handling is much easier in horizontal (h)CoFGE, where
the marker wells only have to be punched out from the gel on
the cathodic side of the pI-strip.
Due to the fixed locations of the marker wells, gel variation in the second dimension is well reflected in CoFGE.