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 drinking. When an alcohol solution is not desirable for this purpose, the alcohol-free Lugol's iodine, an aqueous solution of iodine in potassium iodide solution, or else povidone-iodine (brand names Wokadine, Betadine), a PVPI solution, can be used. Small amounts may be added to suspect drinking water as a disinfectant (typically 5 mg free iodine per liter, or 5 drops of 2% tincture). Though this treatment is effective against bacteria and virus, it does not protect against protozoan parasites such as "Cryptosporidium" and "Giardia". Iodine solution is used to sanitize the surface of fruit and vegetables for bacteria and virus. The