Comparison List


TagRFP-T is a basic (constitutively fluorescent) red fluorescent protein published in 2008, derived from Entacmaea quadricolor. It has low acid sensitivity.
Oligomerization Organism Molecular Weight Cofactor
Monomer Entacmaea quadricolor 27.6 kDa -

FPbase ID: LF3LJ


Ex λ Em λ EC (M-1 cm-1) QY Brightness pKa Maturation (min) Lifetime (ns)
555 584 81,000 0.41 33.21 4.6 100.0 2.3

TagRFP-T OSER Measurements

% Normal Cells OSER/NE ratio Cell Type Reference
41.2 ± 4.0 (10000 cells) - HeLa Cranfill et al. (2016)
43.0 (740 cells) - U-2 OS Manna et al. (2018)


t1/2 (s) Power Light Mode In Cell Fusion ˚C Reference
337.0   Bindels et al. (2016)

TagRFP-T Sequence

TagRFP-T was derived from TagRFP with the following mutations: S2_S2delinsVSKGE/S158T/H230_K231insKLNGMDELY

Note: While the only significant mutation in TagRFP-T relative to the parental TagRFP is S158T, here we show the version with the addition of the EGFP N- and C- termini that is by far the most variant (e.g. on Addgene and SnapGene)

GenBank: ACD03281


Deposited: ,


Negligible photochromic behavior was measured for the mScarlet variants, while TagRFP-T, mRuby2, mRuby3 and mApple showed 15%, 19%, 41%, and 51% photochromic behavior, respectively. Hence, extreme care must be taken when using the latter four RFP variants as acceptors in FRET studies, since a photochromic effect is easily confused with a changed FRET state, especially if one considers that the typical FRET contrast in many sensors is in the range of only 5–20%. The photochromic behavior can also interfere with characterization of FPs, like determination of photostability (Supplementary Fig. 8) or brightness (Supplementary Fig. 5l).

Bindels et al. (2016)

Primary Reference

Additional References

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