Which groups are on your target?
Consider NHS for primary amines and Maleimide for free thiols. For click chemistry, confirm the reaction partners first.
AF488 fluorescent dyes
Green fluorescent labeling with 5 reactive dyes and 4 bioconjugates. Match the target handle to a labeling route and evaluate with 488 nm excitation and green detection.
494nm
517nm
9
Optical values refer to AF488 NHS.
AF488 NHS spectral referenceGreen
AF488 product selection
Find AF488 dyes and conjugates by reactive group or recognition ligand.
Which recognition ligand do you need?
Compare Annexin V, WGA, CTB, Streptavidin; check the sample and conditions.
| Product / catalog no. | Reactive form / ligand | Targets and applications | Documents |
|---|---|---|---|
| AF488 NHS EsterQH-10-1004 | NHS | Antibodies, proteins and other molecules with accessible primary amines | View product → |
| AF488 MaleimideQH-10-1004(Maleimide) | Maleimide | Targets with accessible free thiols | View product → |
| AF488 AzideQH-10-1004(Azide) | Azide | Targets with a compatible alkyne; confirm the click reaction system | View product → |
| AF488-PEG4-DBCOQH-10-1004(DBCO PEG4) | PEG4-DBCO | Azide coupling with a PEG4 spacer | View product → |
| AF488-PEG12-DBCOQH-10-1004(DBCO PEG12) | PEG12-DBCO | Azide coupling; evaluate a PEG12 spacer | View product → |
| AF488-Annexin VQH-10-1004(Annexin V) | Annexin V | Recognizes exposed PS; binding requires Ca²⁺ | View product → |
| AF488 WGAQH-10-1004(WGA) | WGA | Recognizes glycans containing GlcNAc or sialic acid | View product → |
| AF488 CTBQH-10-1004(CTB) | CTB | Recognizes GM1; consider binding and uptake conditions | View product → |
| AF488-StreptavidinQH-15-1004 | Streptavidin | Detect existing biotin labels using Streptavidin | View product → |
Showing 9 / 9 AF488 products
Spectra and detection conditions
AF488 NHS optical properties
- Reference product
- AF488 NHS · QH-10-1004
- Excitation peak
- 494 nm
- Emission peak
- 517 nm
- Molar extinction coefficient
- 73,000 M⁻¹ cm⁻¹
Values refer to this product’s specifications. Consult measurement records for solvent, pH and conjugation state.
Full product specifications →488 nm excitation and green detection
A 488 nm blue laser is a candidate excitation source; the 517 nm emission peak is in the green region. Laser color and fluorescence color describe different stages.
A 530/30 bandpass filter nominally spans 515–545 nm. Confirm actual filters, dichroics, detector response and single-stain controls rather than relying on a channel name.
Read the detection guide →Multicolor combinations and controls
GFP, FITC and AF488 occupy similar green emission regions. A conventional green channel cannot distinguish signals by dye name. Evaluate spillover, autofluorescence, compensation or spectral unmixing in a multicolor design.
Multicolor detection considerations →Match the workflow to the target handle
Bioconjugates
For established recognition ligands, review the corresponding conjugates and their product-specific formulation, dose and storage conditions.
| Product | Recognition target and conditions |
|---|---|
| AF488-Annexin V | Phosphatidylserine; binding is Ca²⁺ dependent. |
| AF488 WGA | GlcNAc- or sialic-acid-containing glycans; consider sample preparation and intracellular signal. |
| AF488 CTB | GM1 ganglioside; confirm the application and treatment conditions. |
| AF488-Streptavidin | Biotinylated targets; account for competing free biotin. |
References
References on reaction chemistry, assay design and result interpretation.
Labeling a protein with fluorophores using NHS ester derivitization
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.
Fluorescent-labeled antibodies: Balancing functionality and degree of labeling
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.
Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)
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.
Technical guides
AF488 · Labeling & detectionAF488 spectra and detection channelsAF488 NHS has 494/517 nm excitation/emission peaks. Check the 488 nm laser and emission filter separately.
Excitation peak and source
AF488 NHS has an excitation peak of 494 nm and an emission peak of 517 nm. A 488 nm blue laser lies nearby; detected signal also depends on absorption at that wavelength, source power and sample concentration. The product name does not give the measured excitation maximum.
Emission-filter collection range
A 530/30 bandpass filter nominally covers 515–545 nm, including the 517 nm peak. Check the dichroic and signals from neighboring dyes in the same window. A wider passband can collect more emission but may also increase spillover and background.
Confirm settings with controls
Check background and signal with unstained and single-stain samples, keeping gain or exposure fixed for comparisons. The peak-position figure cannot calculate compensation or predict brightness; use measured single-stain references for compensation or unmixing.
References
Thermo Fisher · Detection-channel reference
documents.thermofisher.com
Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)
Cossarizza A, Chang HD, Radbruch A, et al. · European Journal of Immunology · 51(12):2708–3145 · 2021
AF488 · Labeling & detectionChannel separation for AF488, GFP and FITCAF488, GFP and FITC can enter the same green window; different names do not establish three independently detectable markers.
Check existing green labels
If the sample already expresses GFP or contains FITC, added AF488 may produce a mixed signal in the same channel. List each label’s spectrum and detection window. One conventional green channel cannot quantify these sources separately.
Decide whether to change a wavelength region
Use unstained and individual single-stain controls to assess actual separation. Compensation or spectral unmixing does not automatically resolve highly similar spectra. If target signals cannot be separated reliably, move one label to a more distant wavelength region.
References
Thermo Fisher · Detection-channel reference
documents.thermofisher.com
Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)
Cossarizza A, Chang HD, Radbruch A, et al. · European Journal of Immunology · 51(12):2708–3145 · 2021
Labeling guide
Read guide →NHS and maleimide labeling routes
NHS labels primary amines; maleimide labels free thiols. Additives and reduction requirements determine sample preparation.
Labeling guide
Read guide →Azide and DBCO click-reaction pairing
Terminal alkynes pair with azides through CuAAC; DBCO pairs with azides through copper-free SPAAC.
Labeling guide
Read guide →Assessment of AF488-labeled conjugates
Compare labeling density, sample recovery, specific signal and background after purification, rather than total fluorescence alone.
Detection and performance assessment of FITC, AF488 and SF488
Distinguish channel matching, signal intensity, photobleaching and pH response.
Product-specific documents
Instructions, SDS, product specifications and CoA are catalog-specific. Request documents on the corresponding product page and include the vial lot number for a CoA.
AF488 NHS Ester
QH-10-1004
AF488 Maleimide
QH-10-1004(Maleimide)
AF488 Azide
QH-10-1004(Azide)
AF488-PEG4-DBCO
QH-10-1004(DBCO PEG4)
AF488-PEG12-DBCO
QH-10-1004(DBCO PEG12)
AF488-Annexin V
QH-10-1004(Annexin V)
AF488 WGA
QH-10-1004(WGA)
AF488 CTB
QH-10-1004(CTB)
AF488-Streptavidin
QH-15-1004
Spectral and selection support
Include the target, reactive handles, buffer formulation, excitation source and emission window to help identify the product and supporting measurement information.
FAQ
Does “488” mean that the excitation peak is exactly 488 nm?
AF488 is a product family name. The NHS product listed here has a 494 nm excitation peak and a 517 nm emission peak; 488 nm is a common laser wavelength. Check the product name, peak and source wavelength separately.
Can it directly replace another brand’s 488 dye?
A similar wavelength region is a starting point for selection, not evidence of identical structure, salt form, molecular weight, solubility or reactivity. Check the new product’s parameters and evaluate conjugation, purification and function at small scale.
Are NHS, Azide and DBCO interchangeable?
They target different handles: NHS for primary amines, Maleimide for free thiols, Azide for terminal or strained alkynes, and DBCO for azides. Confirm the target handle before reviewing the corresponding method.
Should all AF488 products be stored at −20°C?
Reactive dyes and bioconjugates have different storage requirements. The reactive dyes in this catalog are stored dry at −20°C and protected from light; aqueous bioconjugates require the conditions specified on their product page and vial. Confirm storage of prepared solutions separately.
Can this peak-position figure be used to calculate compensation?
The figure marks excitation and emission peaks only, without measured bandwidth or instrument response. Use appropriate single-stain controls and instrument procedures for compensation or unmixing. Specify the product, solvent and application when requesting measured spectra.
Where can I request instructions and a CoA?
Use the Documents tab on the specific product page to request instructions, SDS or calculation parameters. A lot-specific CoA requires the catalog number and vial lot number; this overview supports product and detection selection.