Red fluorescent protein (RFP) is a

fluorophore A fluorophore (or fluorochrome, similarly to a chromophore) is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with se ...

that fluoresces red-orange when excited. Several variants have been developed using

directed mutagenesis Adaptive mutation, also called directed mutation or directed mutagenesis is a controversial evolutionary theory. It posits that mutations, or genetic changes, are much less random and more purposeful than traditional evolution, implying that org ...

. The original was isolated from

Discosoma '' Discosoma nummiforme'' ''Discosoma'' is a genus of cnidarians in the order Corallimorpharia. Common names for the genus include mushroom anemone, disc anemone and elephant ear mushroom.Sprung, JAquarium Invertebrates: Mushrooms, Elephants Ears ...

, and named DsRed. Others are now available that fluoresce orange, red, and far-red. RFP is approximately 25.9 kDa. The

excitation maximum Excitation, excite, exciting, or excitement may refer to: * Excitation (magnetic), provided with an electrical generator or alternator * Excite Ballpark, located in San Jose, California * Excite (web portal), web portal owned by IAC * Electron exc ...

is 558 nm, and the

emission maximum Emission may refer to: Chemical products * Emission of air pollutants, notably: **Flue gas, gas exiting to the atmosphere via a flue ** Exhaust gas, flue gas generated by fuel combustion ** Emission of greenhouse gases, which absorb and emit rad ...

is 583 nm. The first fluorescent protein to be discovered,

green fluorescent protein The green fluorescent protein (GFP) is a protein that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range. The label ''GFP'' traditionally refers to the protein first isolated from the jellyfish ''Aequorea ...

(GFP), has been adapted to identify and develop fluorescent markers in other colors. Variants such as

yellow fluorescent protein Yellow fluorescent protein (YFP) is a genetic mutant of green fluorescent protein (GFP) originally derived from the jellyfish '' Aequorea victoria''. Its excitation peak is 513 nm and its emission peak is 527 nm. Like the parent GFP, YFP ...

(YFP) and

cyan fluorescent protein The green fluorescent protein (GFP) is a protein that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range. The label ''GFP'' traditionally refers to the protein first isolated from the jellyfish '' Aequore ...

(CFP) were discovered in

Anthozoa Anthozoa is a subphylum of marine invertebrates which includes the sea anemones, Scleractinia, stony corals and Alcyonacea, soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plank ...

. Issues with fluorescent proteins include the length of time between protein synthesis and expression of fluorescence. DsRed has an maturation time of around 24 hours, which can make it unusable for many experiments that take place in a shorter time frame. Additionally, DsRed exists in a tetrameric form, which can affect the function of proteins to which it is attached. Genetic engineering has improved the utility of RFP by increasing the speed of fluorescent development and creating monomeric variants. Improved variants of RFP include mFruits (mCherry, mOrange, mRaspberry), mKO, TagRFP, mKate, mRuby, FusionRed, mScarlet and DsRed-Express. DsRed has been shown to be more suitable for

optical imaging Medical optical imaging is the use of light as an investigational :wikt:imaging, imaging technique for medical applications. Examples include optical microscopy, spectroscopy, endoscopy, scanning laser ophthalmoscopy, laser Doppler imaging, and opti ...

approaches than

EGFP The green fluorescent protein (GFP) is a protein that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range. The label ''GFP'' traditionally refers to the protein first isolated from the jellyfish ''Aequorea ...

References

{{reflist

External links

DsRed
on FPBase Fluorescent proteins