Cy3 products include Streptavidin, CTB, WGA, DBCO, Maleimide, Azide, NHS Ester; select for the intended labeling or staining application.
7 products
7 matching products
| Product / Cat. No. | Chemistry | Excitation / nm | Emission / nm | Pack sizes | Product details |
|---|---|---|---|---|---|
| Cy3 NHS EsterQH-30-3001 | NHS Ester | 554 | 566 | 1 mg / 5 mg / 10 mg / 25 mg / 100 mg | |
| Cy3 MaleimideQH-30-3001(Maleimide) | Maleimide | 554 | 566 | 1 mg / 5 mg / 10 mg / 25 mg / 100 mg | |
| Cy3 AzideQH-30-3001(Azide) | Azide | 554 | 566 | 1 mg / 5 mg / 10 mg / 25 mg / 100 mg | |
| Cy3 DBCOQH-30-3001(DBCO) | DBCO | 554 | 566 | 1 mg / 5 mg / 10 mg / 25 mg / 100 mg | |
| Cy3-StreptavidinQH-15-1014 | Streptavidin | 554 | 564 | 1 mg / 5 mg / 10 mg / 25 mg / 100 mg | |
| Cy3 WGAQH-30-3001(WGA) | WGA | 554 | 566 | 1 mg / 5 mg / 10 mg / 25 mg / 100 mg | |
| Cy3 CTBQH-30-3001(CTB) | CTB | 554 | 566 | 1 mg / 5 mg / 10 mg / 25 mg / 100 mg |
Need help with reactive forms or detection channels?
QH-30-3001
| Product / Cat. No. | Form | Ex / Em · nm |
|---|---|---|
| Cy3-StreptavidinQH-15-1014 | Streptavidin | 554 / 564 |
| Cy3 CTBQH-30-3001(CTB) | CTB | 554 / 566 |
| Cy3 WGAQH-30-3001(WGA) | WGA | 554 / 566 |
| Cy3 DBCOQH-30-3001(DBCO) | DBCO | 554 / 566 |
| Cy3 MaleimideQH-30-3001(Maleimide) | Maleimide | 554 / 566 |
| Cy3 AzideQH-30-3001(Azide) | Azide | 554 / 566 |
| Cy3 NHS EsterQH-30-3001 | NHS Ester | 554 / 566 |
Cy3 supplies the fluorescent readout, while the reactive end determines the sample attachment site. Recognition by a preconjugated probe comes from its protein component and follows that probe’s staining application.
Accessible target-bound azide groups
DBCO is a strained alkyne that cycloadds to an azide. Ordinary unmodified proteins lack this paired handle; residual free azide reagents can consume DBCO.
Accessible free thiols
Maleimide adds to a free thiol to form a thioether-containing product. Sulfur in disulfide bonds is not an available free thiol; reduction must preserve the required sample structure and function.
Terminal alkynes or suitable strained alkynes such as DBCO and BCN
An azide dye does not directly label ordinary primary amines or thiols. Identify the target alkyne before choosing copper-catalyzed or strain-promoted cycloaddition.
Protein N-termini, lysine residues and introduced primary amines
The NHS ester forms an amide bond with a primary amine; hydrolysis competes with coupling. Proteins usually contain multiple accessible sites, and the input ratio is not the final degree of labeling.
Accessible sample-bound biotin
Streptavidin binds biotin noncovalently. Free biotin can occupy binding sites, endogenous biotin can cause background, and multivalent binding can crosslink targets.
Accessible ganglioside GM1
CTB is the cholera toxin B subunit and binds GM1 multivalently. The probe can alter GM1 clustering and membrane behavior, so CTB signal alone does not establish lipid-raft number or membrane-domain structure.
Accessible N-acetylglucosamine- and sialic-acid-associated glycans
WGA is wheat germ agglutinin. Signal depends on glycan distribution and accessibility. Fixation, permeabilization, temperature and incubation time affect the observed pattern; signal is not a measure of total membrane amount.
Protein conjugation, local environment and labeling density can alter a Cy-dye readout. Compare signal and background using concentration series of the purified target and check binding or enzymatic function.
Selection criteria
Compare each product’s excitation and emission with the instrument’s light source, filters and detector. A number in a product name does not replace its specifications.
Choose a reactive dye to make a conjugate. For direct staining, select among the listed WGA, CTB or streptavidin conjugates according to their recognition targets.
Titrate the product in the actual sample, matching acquisition and processing conditions and including controls for the application.
Sample and experimental preparation
Record target molecular weight, concentration, available handles and buffer additives. Select a method that separates the target product from free dye, using the product conditions for the actual reactive form.
Handle protein conjugates according to their aqueous formulation and prepare free dyes by catalog number. Record fixation, permeabilization, temperature, incubation and washes for affinity staining.
Retain an unlabeled aliquot from the same preparation. Measure concentration, labeling density and function after purification. Use the actual conjugate for single-color references in multicolor detection.
Free biotin occupies streptavidin-binding sites and can reduce detection of biotinylated targets.
Use unstained, streptavidin-only and non-biotinylated-probe controls to distinguish autofluorescence, endogenous biotin and adsorption.
Multivalent streptavidin can crosslink biotinylated targets, affecting live-cell motion and clustering measurements.
CTB fluorescence reports GM1-associated distribution; puncta alone do not establish native lipid-raft structure.
Distinguish peripheral and intracellular CTB signals over time; one endpoint cannot establish a trafficking route.
Check conjugate-specific application data, tissue background and detection windows before assuming tracing suitability.
WGA labels accessible glycans. Check outline continuity for segmentation; intensity is not a direct measure of membrane amount.
WGA can be internalized by live cells. Interpret intracellular signal using timing and localization.
Fixation and permeabilization can change glycan accessibility. Compare outlines, intracellular signal and background separately.
Target-bound azides enable coupling; free azide reagents and sodium azide can compete for DBCO.
Use product analysis to separate low conversion from detection bias, and a no-azide control to check adsorption.
Terminal alkynes pair with azides through CuAAC; DBCO pairs with azides through copper-free SPAAC.
Cysteines may be disulfide-bound or protected. Confirm free thiols before deciding on reduction.
DTT and β-mercaptoethanol compete for maleimide; residual TCEP can also interfere.
Measure labeling density after removing free dye, then check function and changes during storage.
Use CuAAC for terminal alkynes and SPAAC for strained alkynes. Identify the handle before assessing copper compatibility.
Check reactive handles, catalyst components and copper-binding additives when conversion is low.
Use a no-handle control to distinguish labeling from adsorption, and address free dye and catalyst carryover during purification.
Tris and glycine consume NHS dye. BSA and gelatin require separation from the target protein; routine buffer exchange is insufficient.
Check NHS hydrolysis and amine-containing additives, then distinguish low labeling from sample loss or reduced binding.
Calculate DOL with absorbance correction, distinguish input ratio from attached dye, and assess recovery and binding.
Gruber HJ, Hahn CD, Kada G, et al. · Bioconjugate Chemistry · 11(5):696–704 · 2000
Compares fluorescence changes when Cy3, Cy3.5, Cy5 and Cy7 associate with IgG or avidin, informing joint assessment of labeling density and the purified conjugate’s signal.
DOI: 10.1021/bc000015m
Mujumdar RB, Ernst LA, Mujumdar SR, Lewis CJ, Waggoner AS. · Bioconjugate Chemistry · 4(2):105–111 · 1993
Studies sulfoindocyanine active-ester structures, spectra and labeling of amine-bearing biomolecules, providing background for cyanine NHS-labeling workflows.
DOI: 10.1021/bc00020a001
Howarth M, Chinnapen DJF, Gerrow K, et al. · Nature Methods · 3:267–273 · 2006
Uses an engineered monovalent protein to investigate crosslinking by multivalent binding. It informs assessment of probe valency in membrane-protein motion and clustering studies.
DOI: 10.1038/nmeth861
Cossarizza A, Chang HD, Radbruch A, et al. · European Journal of Immunology · 51(12):2708–3145 · 2021
Provides methodological guidance on detection settings, controls and experimental records for downstream conjugate evaluation.
Thermo Fisher Scientific
Sample preparation, free biotin and background control in biotin-affinity detection.
Kabbani AM, Raghunathan K, Lencer WI, Kenworthy AK, Kelly CV. · PNAS · 117(26):14978–14986 · 2020
Examines how multivalent CTB binding affects GM1 organization and membrane shape, highlighting probe-induced perturbation.
Chazotte B. · Cold Spring Harbor Protocols · 2011(5):pdb.prot5623 · 2011
Describes glycan-dependent membrane labeling with WGA, informing sample preparation and imaging design.
DOI: 10.1101/pdb.prot5623
Debets MF, van Berkel SS, Schoffelen S, et al. · Chemical Communications · 46(1):97–99 · 2010
Reports copper-free reaction of a strained alkyne with azides and its application to enzyme PEGylation.
DOI: 10.1039/b917797c
Agard NJ, Prescher JA, Bertozzi CR. · Journal of the American Chemical Society · 126(46):15046–15047 · 2004
Introduces ring-strain-driven azide–alkyne coupling without copper, a foundational study in SPAAC bioconjugation.
DOI: 10.1021/ja044996f
Shafer DE, Inman JK, Lees A. · Analytical Biochemistry · 282(1):161–164 · 2000
Examines TCEP interactions with reactive groups, informing evaluation of reductant carryover and buffer exchange.
Baldwin AD, Kiick KL. · Bioconjugate Chemistry · 22(10):1946–1953 · 2011
Studies exchange reactions of model adducts in thiol-containing environments to inform conjugate stability assessment.
DOI: 10.1021/bc200148v
Presolski SI, Hong VP, Finn MG. · Current Protocols in Chemical Biology · 3(4):153–162 · 2011
Describes CuAAC catalyst systems and reaction assessment for terminal-alkyne substrates.
Hong V, Presolski SI, Ma C, Finn MG. · Angewandte Chemie International Edition · 48(52):9879–9883 · 2009
Examines ligand, copper catalyst and biomolecule effects to help troubleshoot low CuAAC conversion.
Nanda JS, Lorsch JR. · Methods in Enzymology · 536:87–94 · 2014
Uses FAM ester labeling of a protein to explain primary-amine chemistry and labeling-efficiency assessment. It informs NHS workflow design; input and reaction conditions depend on the actual dye and sample.
Vira S, Mekhedov E, Humphrey G, Blank PS. · Analytical Biochemistry · 402(2):146–150 · 2010
Uses FITC-labeled anti-HA antibody to assess changes in labeling density and antigen binding. It informs input-series design and post-purification functional testing; DOL alone is insufficient for selecting a conjugate.
Request the manual, SDS or lot-specific CoA by catalog number. Include the vial lot number for a CoA.
Product use, preparation, operating conditions and storage.
Lot-specific test methods and results.
Handling, storage and emergency response information.
Identify the sample handle or required recognition mechanism, then select a matching reactive dye or preconjugated probe. Use preparation, reaction and storage requirements for the exact catalog number.
Use values for the exact catalog number. Linker forms and preconjugated products can have different parameters; consult the product table and individual specifications.
Match target concentration, acquisition settings and sample processing. Compare labeling density together with specific signal, negative background, recovery and function; a free-dye or single endpoint measurement does not assess every performance characteristic.
Use molecular weight, an appropriate extinction coefficient and protein-absorbance correction for the exact catalog number after removing free dye. Request parameters not shown on the product page through its Documents tab.
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