DEVELOPMENT OF A DEXTRAN KIT FOR LABELING WITH TC-99M AND ITS EVALUATION FOR LYMPHOSCINTIGRAPHY

A cold dextran (molecular weight 60,000-90,000) kit has been developed by a modified procedure to produce instant preparation of Tc-99m dext ran suitable for lymphoscintigraphy. The preparation was subjected to various quality control measures. Effect of pH and amount of stannous chloride as a reducing agent on the labelling efficiency using ITLC we re studied. The labelled complex was separated from both the reduced p ertechnetate and pertechnetate and quantified. In a series of experime nts hydrolysed/reduced Tc-99m was found to be less than 3.0%, whereas pertechnetate was approx. 1.0%. Biokinetics of the agent in mice and b lood clearance and rate of disappearance from the site of intradermal injection of the agent in rabbits were studied. The tagged agent for i maging of the lymphatic system activated by administering Freund's com plete adjuvant (FCA)/E. coli in rabbits exhibited its suitability for lymphoscintigraphy.