FITC, Fluorescein isothiocyanate

FITC，异硫氰酸荧光素，是荧光素的衍生物。FITC由于其高吸收性，出色的荧光量子产率和良好的水溶性而成为最广泛使用的荧光团之一。FITC的异硫氰酸酯基与蛋白质或抗体分子中的胺，巯基，咪唑基，酪氨酰基或羰基基团结合，该特性用于标记。FITC标记的蛋白质底物/肽，抗体，肽激素分别用作酶动力学，免疫细胞化学，流式细胞仪和靶细胞受体识别的特异性探针。FITC的最大吸收光波长为~495nm，最大发射光波长为~525nm，呈现明亮的黄绿色荧光。

FITC可以用于蛋白质对尿素和热变性的稳定性研究。Fe3O4 @ PS @ P（AEMH-FITC）纳米复合材料可作为MRI造影剂和荧光成像（FLI）试剂用于生物成像[1]。可用异硫氰酸荧光素（FITC）对人胰岛素进行荧光标记[2]。用FITC标记的右旋糖酐分子进行心内灌注可以评估血脑屏障（BBB）的完整性[3]。C3H / HeOu小鼠口服4-kDa FITC右旋糖酐1小时后，其血浆水平可评估小肠的上皮渗透性[4]。

 [1] Wang X, Liu H, Jun R, et al. One-Pot Synthesis of Fe3O4@PS@P(AEMH-FITC) Magnetic Fluorescent Nanocomposites for Bimodal Imaging. J  Nanosci Nanotechnol. 2016 Mar;16(3):2194-200.

[2] Jacob D, Joan Taylor M, Tomlins P, et al. Synthesis and Identification of  FITC-Insulin Conjugates Produced Using Human Insulin and Insulin Analogues for Biomedical Applications. J Fluoresc. 2016 Mar;26(2):617-29.

[3] Natarajan R, Northrop N, Yamamoto B. Fluorescein Isothiocyanate (FITC)-Dextran Extravasation as a Measure of Blood-Brain Barrier Permeability. Curr Protoc Neurosci. 2017;79:9.58.1–9.58.15.

[4] Woting A, Blaut M. Small Intestinal Permeability and Gut-Transit Time Determined with Low and High Molecular Weight Fluorescein Isothiocyanate-Dextrans in C3H Mice. Nutrients. 2018;10(6):685.