Isotachophorese

Isotachophoresis, often abbreviated as ITP, is a type of electrophoresis in which all the charged species in a sample move at the same speed. This is achieved by establishing a stable boundary between a leading electrolyte and a trailing electrolyte, with the sample analytes migrating between them. The key principle is that the electric field strength is uniform across the entire system, and since all charged molecules move at the same velocity, their relative positions are maintained.

In ITP, the sample is introduced between two buffer solutions, a leading electrolyte and a trailing electrolyte. The leading electrolyte contains ions with a higher charge mobility than the sample ions, while the trailing electrolyte contains ions with a lower charge mobility. When an electric field is applied, the ions from the leading electrolyte move fastest, followed by the sample ions, and then the ions from the trailing electrolyte. This creates distinct zones for each component within the sample, effectively separating them based on their charge and mobility.

ITP is a powerful separation technique used in various analytical applications, including the analysis of proteins, nucleic acids, and small molecules. Its ability to achieve sharp zone formation and high separation efficiency makes it suitable for both qualitative and quantitative analysis. The technique can be performed in capillary tubes or on flat gels, offering versatility in experimental design. It is particularly useful for pre-concentration of dilute samples prior to other analytical methods.