iFluor 647 phalloidin

Phalloidin is a cyclic heptapeptide toxin derived from the death cap mushroom (Amanita phalloides). It binds to filamentous actin (F-actin) with high affinity (Kd = 20 nM) and does not bind to globular actin (G-actin). It is commonly used to label F-actin in tissue sections, cell cultures, or cell-free systems for qualitative and quantitative analysis. Phalloidin derivatives also bind to actin filaments from both animal and plant sources, including muscle and non-muscle cells, at a stoichiometric ratio of approximately one phalloidin molecule per actin subunit. Non-specific binding is negligible, providing clear distinction between stained and unstained regions. Therefore, phalloidin derivatives are particularly suitable as a substitute for actin antibodies in related research. Additionally, phalloidin derivatives are small, with a diameter of approximately 12-15 Å and a molecular weight of less than 2000 Daltons. Many physiological properties of actin are maintained, such as the ability to interact with actin-binding proteins like myosin, tropomyosin, and DNase I. Phalloidin-labeled filaments can still penetrate solid myosin matrices, and glycerol-extracted muscle fibers can contract after labeling.

Phalloidin binding inhibits the depolymerization of filamentous actin (microfilaments), stabilizing their structure and disrupting the dynamic equilibrium of polymerization and depolymerization. This property reduces the critical concentration (CC) for actin polymerization to less than 1 µg/mL, making it a potent polymerization promoter. Additionally, phalloidin inhibits the ATP hydrolysis activity of F-actin.

This product is phalloidin labeled with iFluor™ 647, which offers high brightness and photostability. It has strong specificity and high contrast in staining, providing better results than actin antibodies for the qualitative and quantitative detection of F-actin. Phalloidin-iFluor™ 647 Conjugate staining is fully compatible with other fluorescent staining methods used in cell analysis, including fluorescent proteins, Qdot® nanocrystals, and other iFluor™ conjugates (including iFluor™ secondary antibodies). The F-actin bound by this product maintains many of the biological properties of actin itself. Moreover, this product has no species specificity and is widely applicable.

This product is provided as a powder in small granules. Dissolve it in 30 µL of DMSO to prepare a 1 mg/mL solution.

鬼笔环肽（Phalloidin）是一种来源于毒蕈类鬼笔鹅膏（Amanita phalloides）的环状七肽毒素，以高亲和力（Kd= 20 nM）选择性结合于丝状肌动蛋白F-actin，而不会与单体肌动蛋白G-actin结合，通常用来标记组织切片、细胞培养物或无细胞体系中的F-actin，从而对F-actin进行定性和定量分析。另外，鬼笔环肽衍生物也以相近的亲和力结合于大小纤维，无论是动植物来源的肌肉细胞或非肌肉细胞，按照每一个肌动蛋白亚基约与一个鬼笔环肽分子的计量比结合。且非特异性结合几乎可忽略，染色区域和非染色区域辨识度非常明显。因此，鬼笔环肽衍生物特别适合替代肌动蛋白（Actin）抗体进行相关研究。另外鬼笔环肽衍生物很小，直径约12-15Å，分子量＜2000 Daltons，未标记肌动蛋白（Actin）的许多生理特性都得以维持，比如，同肌动蛋白结合蛋白如肌球蛋白，原肌球蛋白，DNase I等仍能发生反应；鬼笔环肽标记的纤维丝仍可穿透固相肌球蛋白基质；以及甘油抽提的肌纤维标记后仍可收缩等。

鬼笔环肽（Phalloidin）的结合阻止丝状肌动蛋白（微丝）的解离，稳定微丝结构，从而破坏微丝的聚合-去聚合的动态平衡。此特性使得肌动蛋白聚合发生的临界浓度（CC）降至＜1 µg/mL，因此，可用作一种聚合促进剂。此外，鬼笔环肽还可抑制F-actin的ATP水解活性。

本品为iFluor™ 647标记的鬼笔环肽，具有高亮度和光稳定性，且染色反应特异性强，对比性高，具有比Actin抗体更好的染色效果，适合用作F-actin的定性和定量检测。iFluor™ 647鬼笔环肽染色与用于细胞分析的其他荧光染色完全兼容，包括荧光蛋白、Qdot® 纳米晶体和其他iFluor™ 偶联物（包含iFluor™ 偶联二抗）。另外，经本品结合后的F-actin仍能维持actin自身具有的许多生物学特性。且本品的结合没有物种差异性，适用性广泛。

本品以粉末小颗粒形式提供，请使用30 uL的DMSO溶解配置成1 mg/mL体系。