Purification is usually done by semi-preparative HPLC, using similar stationary and mobile phases than in the analytical separations. Typically, a single HPLC step will furnish peptide material of 90-95% purity, acceptable for most purposes. Higher purities (~98-99%) will usually require an extra HPLC step.
►Mass spectrometry. In order to detect the target peptide in the synthetic crude and to monitor the subsequent purification steps, MS analysis (LC-MS, MALDI-TOF) is used to ascertain that the measured mass is consistent with the expected composition.
►Other equipment. Additional instrumentation at the facility includes a freeze-drying unit, a multi-channel reader for peptide quantitation, ELISA and other applications, etc. Amino acid analysis for precise quantitation of peptides is also available on an outsourcing basis.