While larger experiments involving more than three gels and time frames between runs of
weeks and months can show variation of mean of 5% and
more, our experiments here using precast gels and pI-strips
from one production batch ran quite reproducibly. In the first
set of three gels when no pI-control was used, variation in
the x-dimension was improved from 2.11% to 1.46%, in the
y-dimension from 1.73% to 0.55%; in the second set of gels
with pI-control from 1.37% to 1.24% and 0.67% to 0.47%, respectively.