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AAT Bioquest

trFluor™ Fluorescent Labeling Dyes and Their Bioconjugates *Optimized for TR-FRET Applications*

TR-FRET assay principle
TR-FRET assay principle using trFluor™ Eu as the donor while Tide Fluor™ 5 (TF5) as the acceptor
Many biological compounds present in cells, serum or other biological fluids are naturally fluorescent, and thus the use of conventional, prompt fluorophores leads to serious limitations in assay sensitivity due to the high background caused by the autofluorescence of the biological molecules to be assayed. The use of long-lived fluorophores combined with time-resolved detection (a delay between excitation and emission detection) minimizes prompt fluorescence interferences.

AAT Bioquest's trFluor™ probes enable time-resolved fluorometry (TRF) for the assays that require high sensitivity. These trFluor™ probes have large Stokes shifts and extremely long emission half-lives when compared to traditional fluorophores such as Alexa Fluor or cyanine dyes. Compared to other TRF compounds, our trFluor™ probes have relatively high stability, high emission yield and ability to be linked to biomolecules. Moreover, our trFluor™ Eu probes are insensitive to fluorescence quenching when conjugated to biological polymers such as antibodies.

Key Features of trFluor™ Dyes:

  • No fluoride addition is required.
  • No enhancing solution is required.
  • Available in a variety of reactive forms.
  • Much easier to be conjugated to biomolecules.
  • Much higher conjugation yield than other TRF dyes.
  • Maximally excited by the common light sources at ~350 nm.
  • trFluor™ Eu dye is optimized to pair with APC, iFluor® 647,TF5, Cy5R, DyLight™ 650 and Alexa Fluor 647.
  • trFluor™ Tb dye is optimized to pair with FITC, iFluor® 488, TF2, DyLight™ 488 and Alexa Fluor 488.

 

Table 1. Typical acceptors for the time-resolved luminescent probes

trFluor™ Donors
Recommended Acceptors
trFluor™ Eu iFluor® 647, TF5, APC
trFluor™ Tb iFluor® 488, FITC, TF2

Table 2. trFluor™ Eu and trFluor™ Tb specifications

Product Name
Ex (nm)
Em (nm)
Ext. Coeff. (cm-1M-1)
CF 280 nm*
CF 260 nm**
trFluor™ Eu 346617~22,0000.7770.911
trFluor™ Tb 330544~20,0000.7970.942
  1. *CF at 260 nm is the correction factor used for eliminating the dye contribution to the absorbance at 260 nm.
  2. **CF at 280 nm is the correction factor used for eliminating the dye contribution to the absorbance at 280 nm (for peptides and protein labeling).

 

trFluor™ Eu TRF Labeling Dye


Excitation and emission of trFluor Eu goat anti-rabbit igg conjugate
The excitation and emission spectra of trFluor™ Eu Goat Anti-Rabbit IgG conjugate in PBS buffer (pH 7.2).
AAT Bioquest's trFluor™ Eu probes enable TRF for the assays that require high sensitivity. The trFluor™ Eu dye has large Stokes shifts and extremely long emission half-lives when compared to more traditional fluorophores such as Alexa Fluor® or cyanine dyes. Compared to other time-resolved fluorescent probes, our trFluor™ Eu probes have relatively high stability, high emission yield and ability to be linked to biomolecules with higher conjugation yield. Moreover, our trFluor™ Eu probes are insensitive to fluorescence quenching when conjugated to biological polymers such as antibodies. To maximize its TR-FRET potential, trFluor™ Eu dye is optimized to pair with APC, iFluor® 647, TF5, Cy5®, DyLight™ 650 and Alexa Fluor® 647.
 

trFluor™ Tb TRF Labeling Dye


Excitation and emission of trFluor Tb goat anti-rabbit igg conjugate
The excitation and emission spectra of trFluor™ Tb Goat Anti-Rabbit IgG conjugate in PBS buffer (pH 7.2).
AAT Bioquest's trFluor™ Tb dye has large Stokes shifts and extremely long emission half-lives when compared to more traditional fluorophores such as Alexa Fluor® or cyanine dyes. Compared to other time-resolved fluorescent probes, our trFluor™ Tb probes have relatively high stability, high emission yield and ability to be linked to biomolecules with higher conjugation yield. Moreover, our trFluor™ Tb probes are insensitive to fluorescence quenching when conjugated to biological polymers such as antibodies. To maximize its TR-FRET potential, trFluor™ Tb dye is optimized to pair with FITC, iFluor® 488, TF2, DyLight™ 488 and Alexa Fluor® 488.
 

Table 3. trFluor™ Fluorescent Labeling Dyes and Kits

Cat No.
Product Name
Ex (nm)
Em (nm)
Unit Size
1300ReadiLink™ Rapid trFluor™ Eu Antibody Labeling Kit *Microscale Optimized for Labeling 50 ug Antibody Per Reaction* 3466172 Labelings
16518trFluor™ Eu goat anti-mouse IgG (H+L) 346617100 ug
16668trFluor™ Eu goat anti-rabbit IgG (H+L) 346617100 ug
1434trFluor™ Eu maleimide 346617100 ug
16925trFluor™ Eu-streptavidin conjugate 346617100 ug
1433trFluor™ Eu succinimidyl ester 3466171 mg
16519trFluor™ Tb goat anti-mouse IgG (H+L) 330544100 ug
16669trFluor™ Tb goat anti-rabbit IgG (H+L) 330544100 ug
16926trFluor™ Tb-streptavidin conjugate 330544100 ug