Ion Exchange Chromatography (IEC) - A gradient pushed separation primarily based on the cost of the protein and its relative affinity amino acids supplier for pharmaceuticals the chemical backbone of the column. Previous to reaching their pI, protein mobility additionally depends upon dimension, conformation, steepness of pH gradient, and the voltage gradient. The protein could be eluted in a decreasing salt gradient, with probably the most hydrophobic proteins eluting from the column final. Two-dimensional Gel Electrophoresis - A kind of electrophoresis in which proteins are separated first in one course by charge followed by a size separation within the perpendicular path. A uniform web detrimental cost is imposed on the molecules by the addition of SDS.