摘要
The Schwartz technique is a simple method for labeling McAb directly with ￣(99m)Tc and can he utilized to design a one-step radiopharmacelltical kit.In this study,it was applied to label anti-human gastric cancer McAb 3H11. The antibody was reduced at room temperature for 30 min with a 1000-fold molar ratio excess of 2mercaptoethanol. The mean labeling efficiency of ￣(99m)Tc3H11 was more than 95%. The immunoreactivity of ￣(99m)Tc-3H11 was more than 80% by ELISA's method. Competition results in vitro showed that ￣(99m)Tc was combined with the high affinity sites of antibody by HPLC. The biodistribution in nude mice bearing 823 gastric cancer xenographts showed that the radioactivity of tumor uptake at 24 h post-injection was the highest except for kidney.The tumor uptake was 8.98±2.42% i.d/g.The count ratio of tumor to blood was over 1.5 and that tumor to liver was more than 2.5 at 24 h post-injection.And the tumor was clearly imaged at 22 h post-injection. The initial clinical results showed that￣(99m)Tc-3H11 was stable in vivo and well good located at the lesion sites.
The Schwartz technique is a simple method for labeling McAb directly with ￣(99m)Tc and can he utilized to design a one-step radiopharmacelltical kit.In this study,it was applied to label anti-human gastric cancer McAb 3H11. The antibody was reduced at room temperature for 30 min with a 1000-fold molar ratio excess of 2mercaptoethanol. The mean labeling efficiency of ￣(99m)Tc3H11 was more than 95%. The immunoreactivity of ￣(99m)Tc-3H11 was more than 80% by ELISA's method. Competition results in vitro showed that ￣(99m)Tc was combined with the high affinity sites of antibody by HPLC. The biodistribution in nude mice bearing 823 gastric cancer xenographts showed that the radioactivity of tumor uptake at 24 h post-injection was the highest except for kidney.The tumor uptake was 8.98±2.42% i.d/g.The count ratio of tumor to blood was over 1.5 and that tumor to liver was more than 2.5 at 24 h post-injection.And the tumor was clearly imaged at 22 h post-injection. The initial clinical results showed that￣(99m)Tc-3H11 was stable in vivo and well good located at the lesion sites.
