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HOME > Product category > Fluorescent proteins > dimeric Keima570: dKeima570

dimeric Keima570: dKeima570

  • Large Stokes Shift
  • Unique Spectrum

CoralHue® dKeima570, originally cloned from the stony coral Montipora sp.(Komon-sango in Japanese), absorbs light maximally at 440 nm and emits orange-red light at 570 nm. Because of the extremely large Stokes shift (130 nm) of CoralHue® dKeima570, the maximum fluorescence can be obtained by the maximum excitation without sacrificing either excitation or fluorescence.

Although several fluorescent proteins have a large Stokes shift, they have green fluorescence as a result of excitation with UV light at around 380 nm. However, the use of such toxic UV light is not suitable for observation in living organisms. Keima is the first red fluorescent protein having a large Stokes shift.

The combination of orange-red emission, a large Stokes shift, stability at 37°C in eukaryotic cells, and being dimeric make CoralHue® dKeima570 a superb reporter protein for labeling subcellular structures in multicolor fluorescence analyses. The orange-red fluorescence is stable under normal aerobic conditions.

Fluorescent properties

Keima-Red spectrum data files (text files)
dKeima570 excitation (4K)  dKeima570 emission (4K)

Note: The file is in a tab-delimited text format. It contains values of the wavelength (1nm spacing) and brightness (fluorescence intensity peak value normalized to 1). Use a spreadsheet program to create a spectrum that will help you in choosing the appropriate excitation filter, dichroic mirror and fluorescence filter.

Oligomerization Dimer
Number of amino acid 222
Excit./Emiss. maxima (nm) 440/570
Molar extinction coefficient (M-1cm-1) 14,000 (492 nm)
Fluorescence quantum yield 0.15
Brightness*1 2.1
pH sensitivity pKa=6.5
Cytotoxicity*2 No

*1Brightness: Molar Extinction Coefficient ×Fluorescence Quantum Yield / 1000
*2Toxicity when expressed in HeLa cells



  • Kogure T, Karasawa S, Araki T, Saito K, Kinjo M, Miyawaki A. A fluorescent variant of a protein from the stony coral Montipora facilitates dual-color single-laser fluorescence cross-correlation spectroscopy. Nat Biotechnol. 2006 (5):577-81. PMID: 16648840

※CoralHue® fluorescent proteins were co-developed with the Laboratory for Cell Function and Dynamics, the Advanced Technology Development Center, the Brain Science Institute, RIKEN. MBL possesses the license and deals in the products.

Please send us a completed and signed License Acknowledgement.

Please note that the product will be shipped after we receive a completed and signed License Acknowledgement (PDF file on the right). Prior to shipping, our staff may contact you to verify the intended use of the product. Please also note that a separate agreement or a contract may be required depending on the intended use.
The product you have ordered is sold for research purpose only. It is not intended for industrial or clinical use, and shall not be used for any purposes other than research. You are also asked not to hand over or resell the product to a third party.
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