Distinguishing Ile/Leu variant ligands in the immunopeptidome using hybrid ExCID fragmentation on SCIEX accurate mass instrument

Date: 26 August 2026

Time: 1:00 p.m. AEST (Sydney/Melbourne) | 11:00 a.m. SGT

Accurate identification of immunopeptides is essential for understanding immune recognition in cancer. In this webinar, Reza presents how hybrid ExCID fragmentation (EAD+CID) on SCIEX ZenoTOF platforms enables the differentiation of isobaric isoleucine (Ile) and leucine (Leu) peptide variants in immunopeptidomics workflows. He also highlights the importance of chromatographic optimization for detecting naturally presented Ile/Leu sequence variants, demonstrating how advanced MS technologies can improve confidence in antigen identification.

Key Learning Points:

• Learn how hybrid ExCID fragmentation can distinguish isobaric Ile and Leu residues in immunopeptides
• Understand how the combination of EAD and CID improves peptide sequence characterization and identification confidence
• Discover why chromatographic optimization is critical for detecting naturally presented Ile/Leu variants in the immunopeptidome

Speaker

Reza (Mohammadreza) Dorvash, Ph.D.

Postdoctoral Researcher
Bio21 Molecular Science and Biotechnology Institute