Darken The Room As Much As Possible – The Darker The Room, The Easier It Will Be To Detect The Dried Urine. Dried Urine Has A Characteristic Dull Yellow Fluorescence Or Glow. This Will Help You To Distinguish It From Other Compounds That May Also Glow. For Example, Some Soaps And Detergents Will Leave Residue That Glows Bright White To An Almost Blueish White, And Lint Can Glow A Very Bright White.