IMPROVED DETECTION SYSTEM FOR WHOLE COLUMN DETECTION IN CAPILLARY ISOELECTRIC-FOCUSING

An improved whole capillary scanning device was constructed which perm itted the scanning of capillaries. This device allowed examination of electropherograms during the course of development, as well as elimina ted the need to handle the capillaries after separation. The scanning device consisted of a detector constructed around the capillary, which was laterally driven by a DC motor via a rubber belt along polished s teel rail. This design produced noise levels better than the earlier p rototype on a separation of test proteins. The S/N ratio is close to t hat of static detection, provided a bare fused silica capillary is sca nned. UV transparent capillaries still produced unacceptable noise lev els, probably due to optical inhomogeneities in the outer coating whic h exaggerated minor positional changes due to vibration.