On labelling membranes.
D002462:Cell Membrane; D002463:Cell Membrane Permeability; D004912:Erythrocytes / Q000166:cytology; D007202:Indicators and Reagents; D007553:Isotope Labeling; D010761:Phosphorus Radioisotopes; D013462:Sulfur Radioisotopes
D007202:Indicators and Reagents; D010761:Phosphorus Radioisotopes; D013462:Sulfur Radioisotopes