Hi Just a quick question, well hopefully a quick one. I'm performing an assignment of a protein and I have recorded an HNCACB and an HNcoCACB and I am attempting to use the Protein Sequence Assignment option. I have picked and assigned from roots and also assigned the non root dim, but I am presented with the error message: Neither query nor matches spectrum contains i -> i-1 specific experiments. Another minor point is that analysis seems to have assigned peaks that appear in both the HNcoCACB and the HNCACB as i peaks and not i-1 peaks. Is it possible to use these spectra with the Protein Sequence Assignment box? Regards Simon -- Simon P Skinner Protein Chemistry Group Leiden Institute of Chemistry, Universiteit Leiden Phone: +31 71 527 6089 / Fax: +31 71 527 4349 E-mail : [log in to unmask]