CY3 (Synonyms: Sulfo-Cyanine3)

Name: CY3
Brand: MedChemExpress
SKU: HY-D0822
Rating: 5.0 (4 reviews)

Cat. No.: HY-D0822 Purity: 99.87%: Data Sheet
COA

SDS
Handling Instructions
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Cy3 (Sulfo-Cyanine3) is an orange-fluorescent label for protein and nucleic acid (λ_ex=554, λ_em=568).

For research use only. We do not sell to patients.

CAS No. : 146368-13-0

Size	Stock	Quantity
Solid + Solvent (Highly Recommended)
10 mM * 1 mL in Water ready for reconstitution	In-stock	Estimated Time of Arrival: December 31
Solution
10 mM * 1 mL in Water	In-stock	Estimated Time of Arrival: December 31
Solid
1 mg	In-stock	Estimated Time of Arrival: December 31
5 mg	In-stock	Estimated Time of Arrival: December 31
10 mg	In-stock	Estimated Time of Arrival: December 31
25 mg	In-stock	Estimated Time of Arrival: December 31
50 mg	In-stock	Estimated Time of Arrival: December 31
100 mg	In-stock	Estimated Time of Arrival: December 31
200 mg	Get quote
500 mg	Get quote

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Customer Review

Based on 4 publication(s) in Google Scholar

Other Forms of CY3:

CY3 (solution) Get quote

4 Publications Citing Use of MCE CY3

Cell Imaging/Staining

: CY3 purchased from MedChemExpress. Usage Cited in: ACS Nano. 2025 Feb 18;19(6):6282-6298. [Abstract]; Representative fluorescence images showing the uptake of Cy3-labeled CRUPPA19 (red) by A20 cells and normal monocytes (L929) after 30 min of incubation. Nuclei were stained with 4′,6-diamidino-2-phenylindole (DAPI) (blue). Scale bar: 20 μm.

: CY3 purchased from MedChemExpress. Usage Cited in: Nat Commun. 2025 Apr 24;16(1):3855. [Abstract]; Fluorescence images of in vitro mixtures of His-YAP-mEGFP (green) and His-MED15-CY3 (red) at the indicated module concentrations in 10% PEG solution, incubated overnight at 4°C on a shaker.

: CY3 purchased from MedChemExpress. Usage Cited in: Nat Commun. 2025 Apr 24;16(1):3855. [Abstract]; The plot shows the mean droplet size. DIC images of the His-YAP-mEGFP and His-MED15-CY3 mixture (1:1 at 5 µM, in 10% PEG) show numerous droplets at room temperature in a coverslip chamber.

: CY3 purchased from MedChemExpress. Usage Cited in: Adv Sci (Weinh). 2025 May 2:e2504768. [Abstract]; Confocal microscopy image of macrophages phagocytosing MI@UN. Nuclei were stained with DAPI (blue), MM with DiO (green), IL-10 with CY3 (red), and NO-prednisolone with CY5.5 (magenta). Scale bar: 20 µm.

: CY3 purchased from MedChemExpress. Usage Cited in: Mater Today Bio. 2025 Jun 27:33:102030. [Abstract]; Time-dependent cellular uptake of the Cy3-labeled, GA-loaded nanoplatform (red) in 4T1 cells, visualized by CLSM. Nuclei were stained with DAPI (blue). Scale bar: 100 µm.

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Description

Cy3 (Sulfo-Cyanine3) is an orange-fluorescent label for protein and nucleic acid (λ_ex=554, λ_em=568).

In Vitro

Guide (The following is our recommended protocol. This protocol is only a guide and should be modified according to your specific needs).
1. Protein Preparation
To obtain the best labeling effect, please prepare the protein (antibody) concentration to 2 mg/mL.
1.1 The pH value of the protein solution should be 8.5 ± 0.5. If the pH is lower than 8.0, adjust it with 1 M sodium bicarbonate.
1.2 If the protein concentration is lower than 2 mg/mL, the labeling efficiency will be greatly reduced. To obtain the best labeling efficiency, it is recommended that the final protein concentration range be 2-10 mg/mL.
1.3 The protein must be in a buffer free of primary amines (such as Tris or glycine) and ammonium ions, otherwise the labeling efficiency will be affected.
Note: Before use, it must be activated with condensation solution (500 μg/mL) (HY-D0178) before subsequent labeling experiments can be performed.
2. Dye Preparation
Dilute the dye with anhydrous DMSO to prepare a clear stock solution of 10 mg/mL.
3. Calculation of Dye Amount
The amount of dye required for the reaction depends on the amount of protein to be labeled. The optimal molar ratio of dye to protein is approximately 10:1.
Example: Assuming the required labeled protein is 500 μL 2 mg/mL IgG (MW=150,000), and 1 mg of dye is dissolved in 100 μL DMSO, the required dye volume is 4.2 μL. The detailed calculation process is as follows:
1) mmol (IgG) = mg/mL (IgG) × mL (IgG)/MW (IgG) = 2 mg/mL × 0.5 mL/150,000 mg/mmol = 6.7 × 10^-6 mmol
2) mmol (dye) = mmol (IgG) × 10 = 6.7 × 10^-6 mmol × 10 = 6.7 × 10^-5 mmol
3) μL (dye) = mmol (dye) × MW (dye)/mg/μL (dye) = 6.7 ×10^-5 mmol × 630.77 mg/mmol/0.01 mg/μL = 4.2 μL (dye)
Note: We recommend using a dye:protein molar ratio of 10:1. If the concentration is too low or too high, the ratio can be adjusted to 5:1, 15:1, or 20:1.
4. Running the Coupling Reaction
1) Slowly add the calculated volume of freshly prepared 10 mg/mL dye to 0.5 mL of protein sample solution, gently shake to mix, and then briefly centrifuge to collect the sample at the bottom of the reaction tube. Avoid vigorous mixing to prevent denaturation and inactivation of the protein sample.
2) Place the reaction tube in a dark place and incubate gently with shaking for 60 minutes at room temperature. Every 10-15 minutes, gently invert the reaction tube several times to thoroughly mix the reactants and improve labeling efficiency.
5. Purification of Conjugates
The following protocol is an example of purifying dye-protein conjugates using a Labelling Kits Centrifugation-Based Rapid Desalting Column (5KD) (HY-D3014).
5.1 Prepare the desalting column according to the instructions.
5.2 Load the reaction mixture onto the top of the desalting column.
5.3 Once the sample has run below the resin surface, immediately add PBS (pH 7.2-7.4).
5.4 Add more PBS (pH 7.2-7.4) to the target sample to complete column purification. Collect the fraction containing the desired dye-protein conjugate.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Molecular Weight

630.77

Formula

C₃₁H₃₈N₂O₈S₂

CAS No.

146368-13-0

Appearance

Solid

Color

Purple to purplish red

Emission (Em)

570

Excitation (Ex)

550

SMILES

CC(/C(N1CCCCCC(O)=O)=C\C=C\C2=[N+](CC)C(C=CC(S([O-])(=O)=O)=C3)=C3C2(C)C)(C)C4=C1C=CC(S(=O)(O)=O)=C4

Shipping

Room temperature in continental US; may vary elsewhere.

Storage

-20°C, protect from light

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light)

Solvent & Solubility

In Vitro:

DMSO : 100 mg/mL (158.54 mM; ultrasonic and warming and heat to 60°C; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

H₂O : 12.5 mg/mL (19.82 mM; ultrasonic and warming and heat to 60°C)

Preparing
Stock Solutions

Concentration Solvent Mass	1 mg	5 mg	10 mg

1 mM	1.5854 mL	7.9268 mL	15.8536 mL
5 mM	0.3171 mL	1.5854 mL	3.1707 mL
10 mM	0.1585 mL	0.7927 mL	1.5854 mL

View the Complete Stock Solution Preparation Table

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (protect from light). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

Molarity Calculator
Dilution Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

Concentration _(start) × Volume _(start) = Concentration _(final) × Volume _(final)

This equation is commonly abbreviated as: C₁V₁ = C₂V₂

Concentration _(start)

Volume _(start)

Concentration _(final)

Volume _(final)

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage

mg/kg

Animal weight
(per animal)

Dosing volume
(per animal)

μL

Number of animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Calculation results:

Working solution concentration: mg/mL

Purity & Documentation

Purity: 99.87%

Select Batch:

Data Sheet (280 KB) SDS (393 KB)

COA (255 KB) HNMR (142 KB) LCMS (258 KB)

Handling Instructions (2659 KB)

References

[1]. Lehmann B, et al. Fluorogenic "photoclick" labelling of DNA using a Cy3 dye. Org Biomol Chem. 2018 Nov 7;16(41):7579-7582. [Content Brief]

Complete Stock Solution Preparation Table

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg

H₂O / DMSO	1 mM	1.5854 mL	7.9268 mL	15.8536 mL	39.6341 mL
	5 mM	0.3171 mL	1.5854 mL	3.1707 mL	7.9268 mL
	10 mM	0.1585 mL	0.7927 mL	1.5854 mL	3.9634 mL
	15 mM	0.1057 mL	0.5285 mL	1.0569 mL	2.6423 mL
DMSO	20 mM	0.0793 mL	0.3963 mL	0.7927 mL	1.9817 mL
	25 mM	0.0634 mL	0.3171 mL	0.6341 mL	1.5854 mL
	30 mM	0.0528 mL	0.2642 mL	0.5285 mL	1.3211 mL
	40 mM	0.0396 mL	0.1982 mL	0.3963 mL	0.9909 mL
	50 mM	0.0317 mL	0.1585 mL	0.3171 mL	0.7927 mL
	60 mM	0.0264 mL	0.1321 mL	0.2642 mL	0.6606 mL
	80 mM	0.0198 mL	0.0991 mL	0.1982 mL	0.4954 mL
	100 mM	0.0159 mL	0.0793 mL	0.1585 mL	0.3963 mL

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

CY3 Related Classifications

Others

Help & FAQs

Do most proteins show cross-species activity?
Species cross-reactivity must be investigated individually for each product. Many human cytokines will produce a nice response in mouse cell lines, and many mouse proteins will show activity on human cells. Other proteins may have a lower specific activity when used in the opposite species.

Keywords:

CY3146368-13-0Sulfo-Cyanine3CY 3CY-3Fluorescent DyeInhibitorinhibitorinhibit

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CY3 (Synonyms: Sulfo-Cyanine3)

Customer Review

Other Forms of CY3:

CY3 Related Antibodies

4 Publications Citing Use of MCE CY3

Featured Recommendations

•Related Small Molecules:

•Related Proteins:

Biological Activity

Purity & Documentation

References

Customer Review

CY3 Related Antibodies

Molarity Calculator

Dilution Calculator

Complete Stock Solution Preparation Table

CY3 Related Classifications

Keywords:

Your Recently Viewed Products:

Customer Review

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SAFETY DATA SHEET (SDS)

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