Fig. 2: The applications of the ballistic sequencing in surface analysis.
From: Protein identification by 3D OrbiSIMS to facilitate in situ imaging and depth profiling
a Sequences of lysozyme (red) and insulin (blue) were simultaneously detected, allowing imaging of a protein mixture. The identified sequences are highlighted in insulin and lysozyme structures, exported from PDB entries 3I4037 and 1AZF38, respectively. b Three proteins were profiled in situ in a human skin sample. The dashed lines indicate borders between the skin layers, assigned based on the profile of phospholipid marker (PO3−). PO3− is presented on a secondary scale for clarity due to high intensity throughout the profile. Example peaks of keratin (stratum corneum and epidermis, blue), corneodesmosin (stratum corneum, red), and collagen (dermis, black). (c) Characteristic lysozyme fragments representing the KVFGRC sequence were detected in a protein biochip, consisting of a protein monolayer immobilized on heptakis-(6-deoxy-6-thio)-β-cyclodextrin (TCD).
