Abstract Background Many cell permeabilisation methods to mediate internalisation of various molecules to mammalian or bacterial cells have been developed. However. no size-specific permeability assay suitable for both cell types exists. Results We report the use of intrinsically biotinylated cell components as the target for reporter molecules for assessing permeabilisation. https://www.alarecre.com/Wizarding-World-Harry-Potter-Scar-and-Glasses-iPhone-13-Pro-MagSafe-Case-p90262/