Autologous IgG were separated from rabbit sera and radiolabeled to perform scintigraphy. The IgG separation was accomplished with fast protein liquid chromatography. IgG were directly labeled with 99mTc using stannous tartrate as reducing agent, sterilized with membrane filter and injected into rabbits. The method can be adopted for use in humans. It is suitable for repeated use as there is no danger of allergic reaction in the recipient.