Thanks to all who provided infomation on iodinated proteins. Just to put some concerns to rest, the free iodine is being removed by the use of columns. Regards Alex Zapantis Radiation Safety Officer Queensland University of Technology Health & Safety Section Locked Bag No.2 Red Hill Qld 4059 AUSTRALIA Ph : 61 7 864 3566 fax : 61 7 864 3993 email : a.zapantis@qut.edu.au