PE excitation shown as dotted line and emission shown as solid yellow histogram
5488-561575/26565576(in buffer) 2flow cytometry

R-phycoerythrin (R-PE) is an intensely bright phycobiliprotein isolated from red algae that exhibits extremely bright red-orange fluorescence with high quantum yields. In practical applications, the sensitivity of R-PE conjugates is usually 5 to 10 times greater than those of the corresponding fluorescein conjugates. In addition, R-PE exhibits:

  • Long-wavelength fluorescence emission
  • Large Stokes shifts
  • Quench resistance due to the protein backbone
  • Very high-water solubility
  • Homogeneous structure with defined molecular weights

R-PE is a large molecule used for fluorescence-based detection, primarily in flow cytometry, microarray assays, ELISAs, and other applications that require high sensitivity, but not photostability. We offer a broad range of R-PE products, including primary antibodies, secondary antibodies, streptavidin, and tandem conjugates.

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Experimental data using Phycoerythrin (R-PE)
unicellular ciliate with green and orange tubulin

Figure 1. Flow cytometry histogram showing human mononuclear cells stained with anti-CD4 complexed with Invitrogen R‑phycoerythrin Zenon labeling reagent.

left plot shows CD4 APC positive and PE isotype control in unstimulated cells; right plot shows CD4 APC and IL-2 PE dual positive sample in stimulated cells

Figure 2. Flow cytometry dot plots showing CD4 APC positive cells. Normal human peripheral blood cells were unstimulated (left) or stimulated (right) with Cell Stimulation Cocktail (plus protein transport inhibitors). Cells were intracellularly stained with Anti-Human CD4 APC and Rat IgG2a K Isotype Control PE or Anti-Human IL-2 PE. Viable cells, as determined by Fixable Viability Dye eFluor 780, in the lymphocyte gate were used for analysis.