Dual-opposite injection capillary electrophoresis: Principles and misconceptions.

Dual-opposite injection capillary electrophoresis (DOI-CE) is a separation technique that utilizes both ends of the capillary for sample introduction. The electroosmotic flow (EOF) is suppressed to allow all ions to reach the detector quickly. Depending on the individual electrophoretic mobilities of the analytes of interest and the effective length that each analyte travels to the detection window, the elution order of analytes in a DOI-CE separation can vary widely. This review discusses the principles, applications, and limitations of dual-opposite injection capillary electrophoresis. Common misconceptions regarding DOI-CE are clarified.