This application note illustrates a simple massdirected approach to peptide isolation and discuss the options for improving the efficiency of the purification protocol.
■ Isolation is easily accomplished using the ACQUITY QDa Mass Detector as configured in the Waters AutoPurification System, making it a lower cost alternative for purification of those peptides with monoisotopic masses or multiple charges which fall within the 30–1250 Da mass range of the detector.
■ Columns with different selectivity are sometimes necessary for improving the separation of crude sample mixtures, which ultimately leads to the isolation of higher purity target peptide.
■ Focusing the gradient improves the resolution of closely-eluting or co-eluting peptide impurities, contributing to the ease of target peptide isolation.
■ The ACQUITY QDa Detector can be used to gather mass data on peptidic by-products, which may be useful for optimizing synthesis and cleavage protocols.