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GFP with short fluorescence lifetime

- Green fluorescence
- Short fluorescence lifetime (1300 ps, in vitro)
- Recommended for fluorescence lifetime imaging microscopy (FLIM)
- Fast maturation and high photostability

SLIM (Shortened Lifetime Imaging Marker) is a highly photostable green fluorescent protein with fluorescence lifetime shortened/reduced relative to the common GFPs (1300 ps vs 2.5-3 ns) [Mamontova et al., 2018]. SLIM carries glycine-tyrosine-glycine (GYG) chromophore and demonstrates fast chromophore maturation under physiological conditions. It also shows weak reactivity in excited-state redox-chemistry and thus – low phototoxicity.

For multiparameter FLIM in green channel SLIM can be used with fluorescent proteins with similar fluorescence spectra and different fluorescence lifetimes: BrUSLEE (800 ps), SLIM (1.3 ns), TagGFP2 (3.2 ns).

Main properties

SLIM spectra

SLIM normalized excitation (thin line) and emission (thick line) spectra.

Download SLIM spectra (xls)

* Brightness is a product of extinction coefficient and quantum yield, divided by 1000.
Molecular weight, kDa27
Polypeptide length, aa239
Fluorescence colorgreen
Excitation maximum, nm488
Emission maximum, nm508
Quantum yield0.06
Extinction coefficient, M-1cm-170 000
Brightness, % of EGFP13
Fluorescence lifetime, ps1300
Fluorescence intensity decaynearly single-exponential
Maturation rate at 37°Cfast
Cell toxicitynot observed
Main advantagesgreen fluorescent protein with shortened fluorescence lifetime

Recommended filter sets and antibodies

The protein can be recognized using Anti-Tag(CGY)FP antibody (Cat.# AB121) or Anti-GFP antibody (Cat.# AB011) available from Evrogen.

SLIM can be detected using common fluorescence filter sets for EGFP, FITC, and other green dyes. Recommended Omega Optical filter sets are QMAX-Green, XF100-2, XF100-3, XF115-2, and XF116-2.

Performance and use

SLIM can be easily expressed and detected in a wide range of organisms. Mammalian cells transiently transfected with SLIM expression vectors produce bright fluorescence in 16-18 hrs after transfection. No cytotoxic effects or visible protein aggregation are observed.

It can be used in multiparameter FLIM in green channel.

Color-coded fluorescence lifetime imaging microscopy (FLIM) image of live HeLa cells co-expressing BrUSLEE (mitochondria), SLIM (nuclei) and TagGFP2 (cytoplasm).

Color hue indicates mean lifetime at each pixel (red-orange – 750-900 ps, green – 1100-1400 ps, cyan-blue – 2700-3100 ps). Single-photon fluorescence excitation at 488 nm was used to acquire these images.

Available variants and fusions
VariantDescriptionRelated vectorCat.#
Humanized SLIM SLIM codon usage is optimized for high expression in mammalian cells [Haas et al., 1996], but it can be successfully expressed in many other heterological systems. pSLIM-N FP212


  • Haas J, Park EC, Seed B. Codon usage limitation in the expression of HIV-1 envelope glycoprotein. Curr Biol. 1996; 6 (3):315-24. / pmid: 8805248
  • Mamontova AV, Solovyev ID, Savitsky AP, Shakhov AM, Lukyanov KA, Bogdanov AM. Bright GFP with subnanosecond fluorescence lifetime. Sci Rep. 2018; 8 (1):13224. doi: 10.1038/s41598-018-31687-w. / pmid: 30185895
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