Direct Labelling of Human Immunoglobulin G with Technetium-99m

• Main Authors: Yi-Hua Jan, 詹怡華
• Other Authors: Jem-Mu Lo
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/38346954084314179037

碩士 === 國立清華大學 === 原子科學研究所 === 81 === Based on high affinity and specificity of the antibodies, radiopharmaceuticals using antibodies as the carrier of radionuclides can be preferent- ially localized in the target organ. In this study ,Tc-99m is labelled to human immunoglobulin G(IgG) where the antibody is modified by 2-iminothiolane (2-IT) to generate sulfhydryl groups for Tc-99m binding. The reaction parameters for the Tc-99m labelling are investigated and aimed to an optimum preparation of a kit which can be used as a clini- cal imaging agent for diagnosing infection and inflammation. The labelling efficiency and proper- ties of the Tc-99m-IgG previously produced are determined by the following analytical methods: HPLC, ITLC, affinity chromatography, SDS-PAGE, sul- fhydryl determination, cysteine and glutathione challenge reaction etc. According to observed study , the suitable formulation of a kit is that each vial is composed of 1mg of 2-IT modified IgG, 0.25 ml of the saturated solution of tin tartrate,and 1 mg of mannitol before lyophilization. The 2-IT modified IgG is prepared by mixing 2-IT and IgG with the molar ratio of 1100:1, incubated at room temperature for 3 hr, and purified by PD-10 column chromatography. The labelling efficiency of Tc-99m -IgG of the kit reconstituted with a saline solu- tion of TcO4- is higher than 99%, and its immuno- reactivity can reach ca. 85%. The stability of the Tc-99m-IgG is determined by a challenge test with 100 and 1000 molar excess of cysteine and glutath- ione. After incubating at 37 degree for 24hr, the corresponding dissociation of Tc-99m is 13% and 20% in the medium of cysteine, 10% and 20% in the medi- um of glutathione, respectively.