Chromatographic techniques have been used routinely for chemical analysis since the 1950s, and for automated analysis of process streams in process control (process chromatography) since 1961. They have also been extensively developed as rapid and accurate methods of measuring a great variety of thermodynamic, kinetic and other physico-chemical properties. Purolite PCR resins are designed for use in industrial process separation. Purolite Chromalite resins are preferred for laboratory-scale analysis, separation of fermentation media and chemical separations of complex compounds such as proteins and amino-acids.