IDOD-BEADS is from Pierce.

1. Volatile ¹²⁵I₂ may be produced. Work under a chemical hood. Proper protection is also needed when working with ¹²⁵I.

2. Incubate one IDOD-Bead in 0.2 ml of 0.1 M Tris-HCl (pH 7) in a microfuge tube for 5 minutes at room temperature.

3. Add 0.2 mg of purified protein and 0.2 mCi of Na¹²⁵I.

4. Incubate for 15 minutes at room temperature.

5. Remove the solution containing ioiodinated protein.

6. Separate by gel filtration.