放射性核素标记的单克隆抗体的定量测定

Quantitative determination of radionuclide labelled monoclonal antibodies

目的 测定放射性核素标记单克隆抗体（ Ｍｃ Ａｂ） 的含量。方法 应用标记的 Ｍｃ Ａｂ 与靶细胞抗原的结合试验，采用平衡方程式 Ｔ／ Ｂ＝ １ ＋ １／（ Ｋａ· Ｃ） ＋ Ｔ／ Ｃ。 Ｋａ ， Ｔ， Ｂ， Ｃ 分别是结合常数，总的 Ｍｃ Ａｂ 的浓度，结合的 Ｍｃ Ａｂ 的浓度及恒定靶细胞抗原的浓度。结果 实验数据说明 Ｔ／ Ｂ 对 Ｔ有极明显的直线相关性。通过直线回归分析，可计算出直线方程。直线与 Ｔ／ Ｂ 轴相交点的 Ｔ／ Ｂ 值的倒数是标记的免疫反应的活性部分。用恒定的标记 Ｍｃ Ａｂ 浓度和不同的未标记的 Ｍｃ Ａｂ 代替 Ｔ，实验结果仍表现 Ｔ／ Ｂ 与未标记的 Ｍｃ Ａｂ 呈明显的直线相关性。此直线与免疫反应活性部分的倒数 Ｔ／ Ｂ 值直线的交点到 Ｔ／ Ｂ 轴的距离就是标记的 Ｍｃ Ａｂ 的实际浓度。结论 本实验方法对放射性核素标记 Ｍｃ Ａｂ

Objective To determine the quantity of radionuclide labelled monoclonal antibodies . Methods Using binding assay for radionuclide labelled Mc Ab with target cell antigen ,the formula of equi librium plot was T/ B= 1 + 1( Ka· C) + T/ C. Ka , T, Band C were the association constants,the concentra tion of total Mc Ab ,the concentration of binding Mc Ab and constant concentration oftarget cell antigen ,re spectively . Results The experimental data demonstrated a very significant linear correlationship of T/ Bto T,and was calculated by m eans oflinear regression analysis . The inverse T/ Bvalue oftheintersecting pointofthe T/ Baxis was the im munoreactive fraction oflabelled Mc Ab . Using constantlabelled Mc Ab concen tration and unlabelled Mc Ab concentration substitute for T,the data also demonstrated a very close linearcorrelationship of T/ Bas a function of unlabelled Mc Ab . The distance from theintersecting point ofthis linewith T/ Bline ofim munoreactive fraction to T/ Baxis was the actual concentration ofin munoreactive frac tion of labelled Mc Ab . Conclusion The above method is feasible as a quantitive determination of radionu clide labelled Mc Ab .( Shanghai Med J,1992 ,22 :457 459)