Use of wide-bore capillaries in constant denaturant capillary electrophoresis.

A serious limitation of capillary electrophoresis in separating mutant from wild-type DNA sequences is the amount of DNA which may be loaded on narrow-bore columns. Because we sought to examine mutant sequences derived from more than 10(9) human cells, we were obliged to overcome this limitation. Thus we examined the feasibility of using wide-bore capillaries of 250, 320 and 540 microns in constant denaturant capillary electrophoresis (CDCE) using conditions which successfully limited the effect of Joule heating. Excellent separations were observed using the wide-bore capillaries comparable to those obtained using a 75 microns capillary. DNA loading capacities were increased almost 100-fold as the bore of capillary increased from 75 to 540 microns.