| Summary: | 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.
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