水溶性CdTe量子点-广谱抗细胞角蛋白单克隆抗体荧光探针的制备及其对肝癌细胞HepG2的免疫荧光标记

Preparing of water soluble CdTe-Pan CK monoclonal antibody fluorescent probes and immunofluorescent labeling of liver cancer cells HepG2

目的制备水溶性CdTe量子点-广谱抗细胞角蛋白单克隆抗体(QDs-MAb)荧光探针,并对其特异免疫性识别能力和荧光稳定性进行检测。方法在EDC偶联剂的作用下,将水溶性CdTe量子点与广谱细胞角蛋白单克隆抗体(PanCK)进行了连接;对肝癌细胞HepG2采用免疫细胞化学法和QDs-MAb单抗荧光探针直接免疫荧光标记法观察比较PanCK蛋白在细胞内的分布;将量子点与传统的荧光染料FITC的荧光强度和荧光稳定性进行了比较。结果QDs-MAb单抗荧光探针对HepG2细胞内的PanCK分子具有特异性的识别能力;与FITC相比,QDs-MAb荧光探针荧光度更强,光化学稳定性更好,激发光连续照射30min及室温放置3d后均未见明显淬灭。结论本实验成功制备了QDs-MAb荧光探针,为半导体量子点用于上皮来源的肿瘤细胞内PanCK分子的相关检测提供了科学依据。

Objective To prepare semiconductor quantum dots（QDs）-Pan CK monoclonal antibody fluorescent probes and then to detect the ability to specific recognition of Pan CK in HepG2 cells.Methods QDs-Pan CK fluorescent probes were prepared by linking water soluble CdTe and Pan CK monoclonal antibody through EDC coupling reagents and then the probes were purified.The expression of Pan CK protein in HepG2 cells was observed by immunocytochemistry and direct immunofluorescence labeling by QDs-Pan CK,and was compared with FITC indirect immunofluorescence labeling.Results Water soluble CdTe and Pan CK monoclonal antibody formed stable fluorescent probes through covalent bond and the probe could recognize specifically Pan CK protein in HepG2 cells and were superior to traditional organic fluorescence dyes in sensitivity and photostability.The signals of QDs showed no obvious change during the continuous illumination by excition light for 30min and after 3 d preserved in room temperature.Conclusions QDs-Pan CK fluorescent probes are prepared successfully which provide new methods for diagnosis and prognosis for epithelial-derived tumor.