New approach to calculating and predicting the ionic strength generated during carrier ampholyte isoelectric focusing

A serious drawback of the carrier ampholyte isoelectric focusing is the undetermined ionic strength at which the proteins separate. We tried to study its effect in order to bridge the gap between theory and practice giving a quantitative and qualitative description. Using certain electrode systems, we managed to calculate the discrete values of the ionic strength in a random position between the electrodes. As a rule, higher values of up to 10−3 mol/l were obtained near the electrodes, which gradually decreased towards the middle of the carrier reaching 10−7 mol/l. A relationship between the measured isoelectric points (pI) of some proteins and the ionic strength was found. In the present paper, we report our findings on the dynamics of the process referring to the origin of ionic strength, its formation and alteration during the isoelectric focusing process.