CY5红色荧光为什么推荐用Fluor647替代？

Fluor647荧光染料的光谱几乎与Cyanine5光谱完全一致，因此为Cyanine5设计的光学滤光片的匹配度也可达到最佳。然而，Fluor647抗体偶联物总荧光强度通常会明显高于Cyanine5偶联物。并且Fluor647与大多数蛋白质、寡核苷酸和核酸偶联时，其吸光度或荧光光谱几乎没有变化，因此在相同的取代程度下，总荧光强度更高，是Cyanine5的优良替代物。

图1: Fluor647激发和发射光谱图

图2: Fluor647及近似染料光谱（APC, Cy5）对比

图3: 对Fluor647和Cy5荧光染料抗体偶联物亮度的比较。显示Fluor 647偶联物的亮度远高于使用Cy5偶联物的亮度。

应用参考文献：

1. Liming Ou, Qingyu Lv, Canjun Wu, Huaijie Hao. Development of a lateral flow immunochromatographic assay for rapid detection of Mycoplasma pneumoniae-specific IgM in human serum specimens.J Microbiol Methods. 2016 May:124:35-40.

2. N Panchuk-Voloshina , R P Haugland, J Bishop-Stewart. Alexa dyes, a series of new fluorescent dyes that yield exceptionally bright, photostable conjugates. J Histochem Cytochem. 1999 Sep;47(9):1179-88.

3. Ryo Tsumura , Ryuta Sato , Fumiaki Furuya.Feasibility study of the Fab fragment of a monoclonal antibody against tissue factor as a diagnostic tool.Int J Oncol. 2015 Dec;47(6):2107-14.

4. Comparison between photostability of Alexa Fluor 448 and Alexa Fluor 647 with conventional dyes FITC and APC by flow cytometry. Int J Lab Hematol. 2018 Jun;40(3):e52-e54.

EnkiLife（恩玑生命）小分子荧光染料标记试剂盒