Proteoform Thursday – Pei Su presents “From Tissues to Single Cells: Direct Proteoform Profiling Using Orbitrap-Based Single Molecule Mass Spectrometry”
December 11, 2025 11:00 AM in Eastern Time (US and Canada)
Direct proteoform measurement in biological samples provides a path to proteomics in spatial tissue compartments and single cells at unprecedented sensitivity and throughput. We employ individual ion mass spectrometry (I2MS), an Orbitrap-based charge detection MS technique in conjunction with direct sampling MS approaches for proteoform profiling in spatial tissue compartments and endogenous single cells directly obtained from tissues. In particular, proteoform imaging mass spectrometry (PiMS) using nanospray desorption electrospray ionization (nano-DESI) has enabled highly-multiplexed imaging and identification of kidney and ovarian cancer tissue proteoforms up to 70 kDa at ~20 µm spatial resolution