The observed rate of migration
of a component ()
divided by electric field strength ()
in a given medium.
Mobilities are sometimes expressed with a negative sign, because migration of the solutes or particles generally occurs in the direction opposite to the electrophoretic field (which is taken as reference for that direction).
In a solid support medium, only apparent values can be determined.
PAC, 1994, 66, 891
(Quantities and units for electrophoresis in the clinical laboratory (IUPAC Recommendations 1994))
on page 894
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook