What are the basic steps in single-step capillary isoelectric focusing?

Single-Step CIEF: 

1. Sample Introduction: Inject a mixture of sample proteins and carrier ampholytes into the capillary as a single plug at the inlet. The capillary is then placed between two electrolyte tanks: one acidic (anolyte) and one basic (catholyte). These tanks create an electric field when a voltage is applied. 
2. Simultaneous Application of Forces: Apply the electric field and a mobilizing force (like pressure, vacuum, gravity, or electroosmosis) simultaneously. 
3. Formation of pH Gradient and Focusing: As the mixture travels from the inlet to the detection point, a pH gradient forms, and proteins focus at their respective isoelectric points (pI). They focus in a narrow band due to their neutral charge at that pH.
4. Detection: The entire capillary is monitored using techniques such as UV absorbance or native fluorescence to visualize the separated protein bands. This allows for tracking the focusing of specific protein species over time.