iFluor® 555 alkyne

iFluor® 555 Alkyne is an orange-fluorescent, click chemistry-reactive dye for covalent labeling of azide-modified molecules and biomolecules in fluorescence-based research applications.

Alkyne Functionality: Selectively reacts with azide groups through click chemistry.
Spectral Properties: Excitation at 557 nm and emission at 570 nm.
pH Sensitivity: iFluor® 555 fluorescence remains stable across pH 3–11.
Applications: Suitable for fluorescent modification of azide-functionalized molecules and biomolecular conjugates.

<p>Click chemistry is a method for attaching a probe or substrate of interest to a specific biomolecule, a process called bioconjugation. The possibility of attaching fluorophores and other reporter molecules has made click chemistry a very powerful tool for identifying, locating, and characterizing both old and new biomolecules. The classic click reaction is the copper-catalyzed reaction of an azide with an alkyne to form a 5-membered heteroatom ring, this reaction is commonly called Cu(I)-Catalyzed Azide-Alkyne Cycloaddition (CuAAC).</p>

Datasheet

SDS

Catalog	Size	Price	Quantity
1092	1 mg	Price

Overview

AAT Bioquest's iFluor® dyes are optimized for labeling proteins, particularly antibodies. These dyes are bright, photostable, and have minimal quenching on proteins. They can be well excited by the major laser lines of fluorescence instruments (e.g., 350, 405, 488, 555, and 633 nm). iFluor® 555 dyes have fluorescence excitation and emission maxima of ~557 nm and ~570 nm respectively. The iFluor® 555 family has spectral properties essentially identical to those of Cy3® (Cy3® is the trademark of GE Healthcare). Compared to Cy3 probes, the iFluor® 555 family has much stronger fluorescence and higher photostability. Their fluorescence is pH-independent from pH 3 to 11. These spectral characteristics make this new dye family a superior alternative to Cy3®. iFluor® 555 family has become an excellent replacement for Cy3® and Alexa Fluor® 555 labeling dye (Cy3® and Alexa Fluor® are the trademarks of Invitrogen and GE Health Care). iFluor® 555 alkyne is reasonably stable and shows good reactivity and selectivity with the azido group in click chemistry.

Calculators

Common stock solution preparation

Table 1. Volume of DMSO needed to reconstitute specific mass of iFluor® 555 alkyne to given concentration. Note that volume is only for preparing stock solution. Refer to sample experimental protocol for appropriate experimental/physiological buffers.

	0.1 mg	0.5 mg	1 mg	5 mg	10 mg
1 mM	93.875 µL	469.373 µL	938.747 µL	4.694 mL	9.387 mL
5 mM	18.775 µL	93.875 µL	187.749 µL	938.747 µL	1.877 mL
10 mM	9.387 µL	46.937 µL	93.875 µL	469.373 µL	938.747 µL

Molarity calculator

Enter any two values (mass, volume, concentration) to calculate the third.

Mass (Calculate)		Molecular weight		Volume (Calculate)		Concentration (Calculate)		Moles
mg	÷	1065.25 g/mol	=	mL	x	mM	=	mmol

Citations

View all 6 citations: Citation Explorer

Intranasal Drop of Multiplex RNA Therapy for SARS-CoV-2 Infections: Baicalein-Enhanced FEN1 Nuclease Cleaving as a Virus Buster

Authors:

Cao, Jiyanuo and Wan, Meng and Gu, Jiayu and Wang, Peiliang and Gao, Yuan and Wei, Libin and Guo, Yongjian and Zhao, Lingzhi and Xu, Shu

Journal:

Emerging Microbes \& Infections (2026): 2706349

Structural mechanism of biased activation of T cell receptor by a high-affinity antibody

Authors:

Li, Xiang and Huang, Buliao and Shao, Enze and Zhu, Yuwei and Yang, Dehui and Chen, Yan and Gao, Wenbo and Lu, Zebin and Lu, Fengliang and Zhang, Anqi and others,

Journal:

Vita (2026)

Three-dimensional printed PCL/nHA scaffolds promote soft tissue functional fibrosis to repair chest wall defect via Piezo1/Ca2+ signal during respiratory motion

Authors:

Zhang, Yuanquan and Li, Xing and Meng, Zijie and Ma, Minghai and Huang, Rou and Liang, Xiao and Liu, Sida and Wei, Wenyuan and Huo, Yangfan and Li, Yizhang and others,

Journal:

Bioactive Materials (2026): 846--861

Deep Sequencing Analysis of the Eha-Regulated Transcriptome of Edwardsiella tarda Following Acidification

Authors:

Gao, D and Liu, N and Li, Y and Zhang, Y and Liu, G and others, undefined

Journal:

Metabolomics (Los Angel) (2017): 2153--0769

Suramin inhibits cullin-RING E3 ubiquitin ligases

Authors:

Wu, Kenneth and Chong, Robert A and Yu, Qing and Bai, Jin and Spratt, Donald E and Ching, Kevin and Lee, Chan and Miao, Haibin and Tappin, Inger and Hurwitz, Jerard and others, undefined

Journal:

Proceedings of the National Academy of Sciences (2016): E2011--E2018

References

View all 49 references: Citation Explorer

Sequential ordering among multicolor fluorophores for protein labeling facility via aggregation-elimination based beta-lactam probes

Authors:

Sadhu KK, Mizukami S, Watanabe S, Kikuchi K.

Journal:

Mol Biosyst (2011): 1766

Visualizing dengue virus through Alexa Fluor labeling

Authors:

Zhang S, Tan HC, Ooi EE.

Journal:

J Vis Exp. (2011)

Fluorescent "Turn-on" system utilizing a quencher-conjugated peptide for specific protein labeling of living cells

Authors:

Arai S, Yoon SI, Murata A, Takabayashi M, Wu X, Lu Y, Takeoka S, Ozaki M.

Journal:

Biochem Biophys Res Commun (2011): 211

Neuroanatomical basis of clinical joint application of "Jinggu" (BL 64, a source-acupoint) and "Dazhong" (KI 4, a Luo-acupoint) in the rat: a double-labeling study of cholera toxin subunit B conjugated with Alexa Fluor 488 and 594

Authors:

Cui JJ, Zhu XL, Ji CF, Jing XH, Bai WZ.

Journal:

Zhen Ci Yan Jiu (2011): 262

Simultaneous detection of virulence factors from a colony in diarrheagenic Escherichia coli by a multiplex PCR assay with Alexa Fluor-labeled primers

Authors:

Kuwayama M, Shigemoto N, Oohara S, Tanizawa Y, Yamada H, Takeda Y, Matsuo T, Fukuda S.

Journal:

J Microbiol Methods (2011): 119

Physical properties

Molecular weight	1065.25
Solvent	DMSO

Spectral properties

Correction factor (260 nm)	0.23
Correction factor (280 nm)	0.14
Extinction coefficient (cm ^-1 M ^-1)	100000 ¹
Excitation (nm)	557
Emission (nm)	570
Quantum yield	0.64 ¹

Usage and storage

Intended use	Research Use Only (RUO)
Storage	Freeze (< -15 °C); Minimize light exposure

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Page updated on October 28, 2026