Iodine-125 Radionuclide, 1mCi, Specific Activity: ~17Ci/mg, 0.1M NaOH (pH 12-14)

Iodination of proteins is a common method of adding a tracer with high specific activity to your protein of interest. Several different methods are available, and these differ in terms of the amino acids that become labeled and in the reaction conditions that are used. Iodine isotopes have relatively short half-lives (60 days for ¹²⁵I and 8 days for ¹³¹I). In addition, iodine-labeled proteins are subject to loss of activity and physical degradation due to the isotopic decay. For these reasons, iodine-labeled proteins generally should be used as soon as possible, generally within 30 days or less after labeling.