Urinary protein isolation by high-performance ion-exchange chromatography.

Proteins excreted in urine, following renal failure, were analysed by high-performance anion-exchange chromatography and chromatofocusing. The analysis involved three steps: (1) removal of the low-molecular-weight fraction by rapid desalting, (2) anion exchange of the high-molecular-weight fraction by using combined salt and pH gradients and (3) further separation of the main peaks by chromatofocusing. The selection of the column and conditions were based on data obtained from electrophoretic titration curves. The purity of selected peaks was evaluated by sodium dodecyl sulphate polyacrylamide gel electrophoresis.