Cy5 NHS ester

Cy5 NHS ester(Cyanine5 NHS ester) is a Red emitting fluorescent dye for labeling of amino-groups in peptides, proteins, and oligonucleotides^[1]. The excitation and emission at 646 and 669nm, respectively^[2].

Cy5 NHS ester solution at 10 mg/ml in DMSO. Cy5 NHS ester amine-reactive red emitting fluorescent dye was used to react with the free amino group on the cysteine amino acid present in terminal peptides used for end-capping pBAEs backbones^[1]. On the other hand， 1 mg of Cy5 NHS ester dye was dissolved in 0.1 ml of 62.5mM sodium tetraborate buffer (pH 8.5). After adding L-methionine in saturation, the mixture was incubated overnight at 4 °C. Fluorophore (Cy5)-conjugated methionine (Cy5-Met) was purified by reverse-phase chromatography on an Agilent HPLC system using a C18 column^[3].

Cy5 NHS ester(Cyanine5 NHS ester) 是一种红色荧光染料，用于标记肽、蛋白质和寡核苷酸中的氨基^[1]。分别在646和669 nm处的激发和发射^[2].

在 DMSO 中浓度为 10 mg/ml 的 Cy5 NHS 酯溶液。 Cy5 NHS 酯胺反应性红色荧光染料用于与末端肽中存在的半胱氨酸氨基酸上的游离氨基发生反应，用于封端 pBAE 主链^[1]。另一方面，将 1mg 的 Cy5 NHS 酯染料溶解在 0.1ml 的 62.5mM 四硼酸钠缓冲液 (pH 8.5) 中。加入饱和的 L-甲硫氨酸后，将混合物在 4°C 下孵育过夜。在安捷伦 HPLC 系统上使用 C18 柱^[3]，通过反相色谱纯化荧光团 (Cy5)-偶联的甲硫氨酸 (Cy5-Met)。

References:
[1].Brugada-Vilà P, Cascante A, et al. Oligopeptide-modified poly(beta-amino ester)s-coated AdNuPARmE1A: Boosting the efficacy of intravenously administered therapeutic adenoviruses. Theranostics. 2020 Feb 3;10(6):2744-2758.
[2].Jiménez Sánchez G, et al. Fluorescent Radiosensitizing Gold Nanoparticles. Int J Mol Sci. 2019 Sep 18;20(18):4618.
[3].Kim JM, Seong BL. Highly chromophoric Cy5-methionine for N-terminal fluorescent tagging of proteins in eukaryotic translation systems. Sci Rep. 2017 Sep 14;7(1):11642.