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iFluor Secondary Reagents

iFluor546 cell stain
iFluor® conjugated secondary antibodies are powerful tools to identify and visualize target proteins in many applications, including fluorescent cell imaging, immunohistochemistry, flow cytometry, western blotting, and ELISA. The exceptional brightness and photostability of our iFluor® dyes combined with the specificity of our cross-adsorbed goat secondary antibodies guarantee consistency and quality, ensuring bright staining of medium-to-low abundance targets with minimal noise. AAT Bioquest offers secondary antibodies conjugated to 28 unique iFluor® dyes covering the entire spectrum with minimal spectral overlap to accommodate multi-color analysis.

In addition to iFluor dyes, we also offer secondary antibodies conjugated to HRP and poly-HRP, biotin, phycobiliproteins and tandem dyes, Alexa Fluor® equivalent XFD dyes, and traditional fluorophores (e.g., FITC, Texas Red®, Cy5, etc.).



iFluor Secondary Antibody Product Guide

Parameter Definition
Detection Strategy Uses indirect detection strategies whereby the secondary antibody detects an unlabeled primary antibody bound to the target of interest.
Applications Designed for use in various cell analysis and protein analysis applications, including cell imaging (e.g., IHC/ICC/IF), fluorescent ELISA, and fluorescent western blotting.
Product Attributes
  • Enhanced sensitivity - multiple iFluor® secondary antibodies can bind to a single primary antibody resulting in signal amplification and an increase in assay sensitivity.
  • pH Insensitivity - iFluor® dyes emit bright fluorescence intensities over a wide range (pH 3 to 11).
  • Excellent Water Solubility - eliminates the precipitation and aggregation of iFluor® secondary antibodies.
  • Increased flexibility when designing multi-color fluorescent western blot panels.
Targets Available Host
  • Goat
Fluorophores Available
Mountants Compatible with the ReadiUse™ microscope mounting solution (Cat No. 20009), the FluoroQuest™ Mounting Medium with DAPI (Cat No. 20004), and most other standard mountants.
Fixatives Compatible with the ReadiUse™ 4% formaldehyde fixation solution (Cat No. 20010) and most other standard fixatives.
Antifade Reagents Compatible with the FluoroQuest™ Anti-fading Kit I optimized for slide imaging (Cat No. 20001) and Kit II optimized for plate imaging (Cat No. 20003), FluoroQuest™ Anti-fading Mounting Medium with DAPI (Cat No. 20005), and most other antifading reagents.
Suitable Counterstains Compatible with most organelle-specific stains such as nuclear counterstains, MitoLite™ dyes, LysoBrite™ dyes, and phalloidin conjugates for F-actin imaging.


iFluor® Secondary Antibodies - Superior Brightness and Photostability

Secondary antibodies labeled with iFluor® dyes exhibit superior brightness, higher signal-to-noise ratios, and improved photostability, outperforming spectrally similar secondary antibody conjugates such as fluorescein and most Alexa Fluor® secondary antibody conjugates. The excellent photostability and pH insensitivity of our iFluor® secondary antibodies ensure fluorescence intensity remains high over a wide molar range and more extended periods of time Figure 1.

Comparison of photobleaching rates of iFluor® 488 goat anti-mouse IgG (Cat No. 16735) versus FITC goat anti-mouse IgG (Cat No. 16852). Images were taken at 120-second intervals on a Keyence X710 fluorescence microscope. TFI represents total fluorescence intensity as calculated by ImageJ software.


Table 1. iFluor® Dyes Spectral Properties

iFluor® Dye
Mol. Wt.
Abs. (nm)
Em. (nm)
CF at 260 nm³
CF at 280 nm⁴
iFluor® 350749.8534545020,0000.950.830.23
iFluor® 405755.5840342737,0000.910.480.77
iFluor® 430688.7943349840,0000.780.680.3
iFluor® 440692.8343448040,000N/D0.3520.229
iFluor® 450603.6945150240,0000.820.450.27
iFluor® 460793.9946849380,0000.80.980.46
iFluor® 488945.0749151675,0000.90.210.11
iFluor® 5141013.9551152775,0000.830.2650.116
iFluor® 532914.0653756090,0000.680.260.16
iFluor® 5461145.41541557100,0000.670.250.15


Product Ordering Information


Table 2. Product ordering information for secondary immunoreagents.

Product Name
Unit Size
11035MegaWox™ polyHRP-Goat Anti-Mouse IgG Conjugate  1 mg
11037MegaWox™ polyHRP-Goat Anti-Rabbit IgG Conjugate  1 mg
11540Amplite® Fluorimetric Goat Anti-Mouse IgG-HRP Conjugate ELISA Assay Kit *Red Fluorescence*5715851000 Tests
11541Amplite® Fluorimetric Goat Anti-Rabbit IgG-HRP Conjugate ELISA Assay Kit *Red Fluorescence*5715851000 Tests
16380XFD350 goat anti-mouse IgG (H+L) *Cross Adsorbed, XFD350 Same Structure to Alexa Fluor™ 350*3464451 mg
16383XFD488 goat anti-mouse IgG (H+L) *Cross Adsorbed, XFD488 Same Structure to Alexa Fluor™ 488*4945171 mg
16388XFD594 goat anti-mouse IgG (H+L) *Cross Adsorbed, XFD594 Same Structure to Alexa Fluor™ 594*5906171 mg
16395XFD350 goat anti-rabbit IgG (H+L) *Cross Adsorbed, XFD350 Same Structure to Alexa Fluor™ 350*3464451 mg
16398XFD488 goat anti-rabbit IgG (H+L) *Cross Adsorbed, XFD488 Same Structure to Alexa Fluor™ 488*4945171 mg
16404XFD594 goat anti-rabbit IgG (H+L) *Cross Adsorbed, XFD594 Same Structure to Alexa Fluor™ 594*5906171 mg