2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/126622We report a new effect of surfactants in pinning a drop contact line, specifically that lysozyme promotes while lauryl sulfate inhibits pinning. We explain the pinning disparity assuming difference in wetting: the protein-laden drop wets a "clean" surface and the surfactant-laden drop wets an auto-precursored surface.3 pages, 4 figuresChemical PhysicsFluid Dynamicstext