Near-infrared fluorescent protein NirFP

- Near-infrared fluorescence with emission maximum at 670 nm
- Extremely high photostability
- Fluorescent signal is easily distinguished from background fluorescence
- Recommended for multicolor applications

Main properties

NirFP normalized excitation (thin line) and emission (thick line) spectra. Spectra viewer tool Download NirFP spectra (xls)

CHARACTERISTIC * Brightness is a product of extinction coefficient and quantum yield, divided by 1000. ** Brightness in infrared is a product of extinction coefficient at 635 nm, quantum yield and emission fraction between 700 nm and 900 nm, divided by 1000. Molecular weight, kDa 26 Polypeptide length, aa 234 Fluorescence color near-infrared Excitation maximum, nm 605 Emission maximum, nm 670 Quantum yield 0.06 Extinction coefficient, M-1cm-1 70 000 Brightness* 4.2 Brightness, % of EGFP 13 Extinction coefficient, M-1cm-1 at 635 nm 15 700 Quantum yield in infrared (700-900 nm) 0.03 Brightness in infrared** 0.47 pKa 4.5 Structure dimer Aggregation no Photostability super high Cell toxicity not observed Main advantages most red-shifted fluorescent protein available; high pH-stability, extremely high photostability Possible limitations dimer, limited applicability for fusions generation; low brightness