Uranyl acetate is extensively used as a negative stain in electron miroscopy. 1% uranyl acetate solutions is used as anindicator, and atitrantin stronger concentrations inanalytical chemistry, as it forms an insoluble salt withsodium(the vast majority of sodium salts are water-soluble). Uranyl acetate solutions show evidence of being sensitive to light, especially UV, and will precipitate if exposed.