Optimizing Immunoprecipitation Workflows for Next-gen Protein Sequencing 

Next-gen protein sequencing (NGPS) on the Platinum® Pro platform enables comprehensive characterization of proteins enriched by immunoprecipitation (IP), including isoforms, sequence variants, and post-translational modifications. NGPS performance depends on optimization of upstream IP workflows and sample preparation conditions. In this study, we evaluated key variables influencing NGPS performance, including elution buffer composition and target protein abundance. Using recombinant human serum albumin (HSA) as a model, we found that commonly used low-pH tris/glycine and citrate/phosphate buffer systems were incompatible with NGPS, resulting in reduced alignments and peptide identification.