Iodine-125 electrons from the radioisotope have been found in one study to do little cellular damage, unless the radionuclide is incorporated chemically directly into cellular DNA, which is not the case for present radiopharmaceuticals which use I-125 as the radioactive label nuclide. As with other radioisotopes of iodine, iodine-125 uptake in the body (mostly to the thyroid) can be blocked with prompt administration of stable iodine-127 in the form of an iodide or iodate salt. Potassium iodide (KI) is typically used for this purpose. Iodine-125 Iodine-125 (I) is a radioisotope of iodine which has uses in biological assays, nuclear medicine imaging
Tincture of iodine by Grossich. He claimed in 1915 that Grossich had been using a liquid akin to Liquor Iodi Fortis, and that it was he, Stretton, who had introduced the method using Tincture of Iodine BP which came to be used across the world. USP Tincture of Iodine is defined in the U.S. National Formulary (NF) as containing in each 100 mL, 1.8 to 2.2 grams of elemental iodine, and 2.1 to 2.6 grams of sodium iodide. Alcohol is 50 mL and the balance is purified water. This "2% free iodine" solution provides about one mg of free iodine per drop. USP