2020-04-07 15:56 Capillary isoelectric focusing(cIEF) will shorten the analysis time and reduce sample consumption. In cIEF, the isoelectric point of protein samples can be detected in situ after the completion of focusing in a capillary. Given the amino acid composition of a protein is known, it is also easy to calculate the theoretical isoelectric point of the protein. Two methods are available at Creative Proteomics for pI determination.