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Midoriishi-Cyan Fluorescent Protein

  • High Fluorescent Quantum Yield
  • Useful for FRET Analysis
  • Labeling of proteins, cells and subcellular structures
  • No protein aggregation

The fluorescent protein Midoriishi-Cyan gene was isolated from the stony coral Acropora sp.(Midori-ishi in Japanese).

CoralHue® Midoriishi-Cyan 1 (MiCy1) absorbs light maximally at 472 nm and emits cyan light at 495 nm. It rapidly matures to form a bright dimeric complex. So it can be used to mark individual cells or to report gene expression without protein aggregation. CoralHue® mMiCy1 is a monomeric version of MiCy1, and can be used to label proteins or subcellular structures. These fluorescent proteins are suitable as donor for fluorescence resonance energy transfer (FRET) because of highly fluorescent quantum yield.

Performance and Use

Monitoring of caspase-3 activity during apoptosis

MiCy and Kusabira-Orange (KO) is a good donor/acceptor pair for FRET (fluorescence resonance energy transfer). FRET based caspase3 monitoring probe is constructed using MiCy and KO, connected by a peptide containing the caspase3 cleavage sequence, DEVD (Asp-Glu-Val-Asp). The activation of caspase3 leads to eliminate FRET by cleavage of DEVD sequence.

Cell: HeLa
Filter, mirror: DM 465HQ, Ex BP440-460HQ, Em BA475-540HQ(cyan), BA555-600HQ(orange)
Lamp: Xe lamp (75W)
Lens: UApo/340 N.A. 1.35
Apoptosis induction: 500 ng/ml of anti-Fas antibody (CH-11; Medical & Biological Laboratories Co.,Ltd.) and 10 μg/ml cycloheximide at 36h post-transfection.


  1. Karasawa S, Araki T, Nagai T, Mizuno H, Miyawaki A, Cyan-emitting and orange-emitting fluorescent proteins as a donor/acceptor pair for fluorescence resonance energy transfer; Biochem J. 381, 307-12(2004) PMID: 15065984

Fluorescent Properties

Midoriishi-Cyan1 spectrum data files (text files)

Note: The file is in a tab-delimited text format. It contains values of the wavelength (0.5nm 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.mido4

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

Recommended antibodies

CoralHue® Midori-ishi Cyan can be recognized using antibodies as shown below.

  • Anti-MiCy for WB, Code No. M130-3M
  • Anti-MiCy for IP, Code No. M116-3M

WB: Western blotting, IP: Immunoprecipitation