Plovins A, Alvarez A M, Ibañez M, Molina M, Nombela C
Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense, Madrid, Spain.
Appl Environ Microbiol. 1994 Dec;60(12):4638-41. doi: 10.1128/aem.60.12.4638-4641.1994.
Fluorescein-di-beta-D-galactopyranoside (FDG) was found to be a useful substrate for beta-galactosidase detection by flow cytometry in gram-negative bacteria, since it entered viable cells and gave a fluorescence emission proportional to the enzymatic activity. C12-FDG, a more lipophilic derivative, gave a very poor signal because of the lack of penetration. On the contrary, C12-FDG was more sensitive than FDG for beta-galactosidase activity determinations in animal cells. In contrast to previous reports, C12-FDG did not enter viable yeast cells, so that the use of the substrate required cell permeabilization. Without this treatment, C12-FDG penetrates only nonviable yeast cells that may occur in populations expressing beta-galactosidase.
荧光素 - 二 - β - D - 吡喃半乳糖苷（FDG）被发现是一种通过流式细胞术检测革兰氏阴性菌中β - 半乳糖苷酶的有用底物，因为它能进入活细胞并发出与酶活性成正比的荧光。C12 - FDG是一种亲脂性更强的衍生物，由于缺乏穿透性，其信号非常弱。相反，C12 - FDG在动物细胞中β - 半乳糖苷酶活性测定方面比FDG更敏感。与之前的报道不同，C12 - FDG不能进入活酵母细胞，因此使用该底物需要使细胞通透化。未经这种处理，C12 - FDG仅能穿透表达β - 半乳糖苷酶的群体中可能存在的非活酵母细胞。
