Capillary electrophoresis of macromolecular biological assemblies: bacteria and viruses

Like other colloidal particles, bacteria and viruses carry charged or charg eable groups on their outer surface creating an electric double layer upon contact with the aqueous phase. This is characterised by the potential, whi ch determines the electrophoretic mobility of the particles in an electric field. Therefore, bacteria and viruses undergo electrophoresis in free solu tion with their migration depending on the ionic strength and the pH of the buffer solution. Differential electromigration can thus be used to separat e and characterise the intact particles and their fragments, either in the zone electrophoretic or in the isoelectric focusing mode. Moreover, interac tion of ligands with their surface might change the potential, enabling the investigation of affinity complex formation of e.g. viruses with antibodie s or neutralising receptors. (C) 2001 Elsevier Science B.V. All rights rese rved.