Protein samples are first premixed with carrier ampholytes, additives and pI markers. Samples are separated in a capillary cartridge with electrolytic tanks at each end—one tank is filled with acid (anolyte) and the other base (catholyte).
The sample mixture is injected to fill the entire capillary column. Voltage is then applied to the anolyte and catholyte tanks. This creates a pH gradient, which separates and focuses the proteins based on their pI. The whole-column UV detector monitors the entire process in the capillary in real time. The focusing time can be optimized in a single sample run, and once it's complete the separation pattern is captured and analyzed. The capillary column is then washed so it's ready to go for the next sample.