SEATTLE: July 15, 2007 -- A tumor paint developed by researchers at Seattle Children? Hospital Research Institute and Fred Hutchinson Cancer Research Center will help surgeons see where a tumor begins and ends more precisely by illuminating the cancerous cells. The study, published in the July 15, 2007 issue of Cancer Research, shows that the tumor paint can help surgeons distinguish between cancer cells and normal brain tissue in the operating room. The paint is a scorpion-derived peptide called chlorotoxin that is linked to the molecular beacon Cy5.5.Until now there has been no way to allow surgeons to see tumors ?ive?during surgery.