Alexa Fluor Brand Overview - US (2024)

Comparison of relative fluorescence of goat anti–mouse IgG antibody conjugates prepared from the Alexa Fluor 488 dye and fluorescein isothiocyanate (FITC). Conjugate fluorescence is measured by comparing the fluorescence quantum yield of the conjugated dye relative to that of a reference dye and multiplying by the dye:protein labeling ratio.

Comparison of relative fluorescence of goat anti–rabbit IgG antibody conjugates of the Alexa Fluor 555 and Cy3 dyes at different dye:protein ratios in the conjugate.

Flow cytometry comparison of the brightness of Alexa Fluor 647 goat anti–mouse IgG antibody (red, A21235) with Cy5 goat anti–mouse IgG antibody from Jackson ImmunoResearch Laboratories (green) and Amersham-Pharmacia Biotech (blue). Human blood was blocked with normal goat serum and incubated with an anti-CD3 mouse monoclonal antibody; cells were washed, resuspended and incubated with either an Alexa Fluor 647 or Cy5 goat anti–mouse IgG secondary antibody. Samples were analyzed on a flow cytometer equipped with a 633 nm He–Ne laser and a longpass emission filter (>650 nm).

Comparison of the photobleaching rates of the Alexa Fluor 488 and Alexa Fluor 546 dyes and the well-known fluorescein and Cy3 fluorophores. The cytoskeleton of bovine pulmonary artery endothelial cells (BPAEC) was labeled with (top series) Alexa Fluor 488 phalloidin and mouse monoclonal anti–a-tubulin antibody in combination with Alexa Fluor 546 goat anti–mouse IgG antibody or (bottom series) fluorescein phalloidin and the anti–a-tubulin antibody in combination with a commercially available Cy3 goat anti–mouse IgG antibody. The pseudocolored images were taken at 30-second intervals (0, 30, 90, and 210 seconds of exposure). The images were acquired with bandpass filter sets appropriate for fluorescein and rhodamine.

Reduced photobleaching, sustained signal. Bovine pulmonary artery endothelial cells were labeled with fluorescein phalloidin (A) or Alexa Fluor 488 phalloidin (B) which label filamentous actin. The cells were placed under constant illumination on the microscope. Images were acquired at one-second intervals for 30 seconds. Under these illumination conditions, fluorescein images are photobleached to about 20% of its initial value, while fluorescence of Alexa Fluor 488 phalloidin stayed at the initial value.

Alexa Fluor Plus 405 conjugates allow for improved signal to noise when compared to traditional Alexa Fluor 405 conjugates. Traditional Alexa Fluor 405 secondary antibody (left) compared to Alexa Fluor Plus 405 secondary antibody (right, goat anti-rabbit IgG secondary antibody, Cat. No. A48254) in immunofluorescent analysis of β-III tubulin in fixed HeLa cells. Nuclei were stained with SYTOX Deep Red stain (Cat. No S11380). The images contain overlay of tubulin (cyan), and nuclei (magenta). Images were taken on an EVOS M7000 Imaging system (Cat. No. AMF7000) at 20x magnification.

Alexa Fluor Plus 555 allows you to see greater detail compared to traditional Alexa Fluor 555 conjugates. Traditional Alexa Fluor 555 secondary antibody (left) compared to Alexa Fluor Plus 555 secondary antibody (right, goat anti-mouse IgG secondary antibody, Cat. No. A32727) in immunofluorescent analysis of β-III tubulin in E18 Sprague Dawley primary cortical neuronal cells. Nuclei were stained with Hoechst 33342 stain (Cat. No. H3570). The image contains overlay of neuronal tubulin (orange) and nuclei (blue). Images were taken on a confocal microscope at 40x magnification.