Labeling and stability study On^99mTc-tissue plasminogen activator as thrombus and tumor imaging agent

Tissue plasminogen activator(tPA),due to its stability in acidic solution,could be conveniently labeled with ^99mTc by using stannous chloride method.More than 90% of biochemical activity was remained after the process of labeling and separation,The stability of ^99mTc-tPA was studied at different time and different pH values,respectively.The study indicated that ^99m Tc-tPA would be a potential imaging agent for thrombus and tumor.