Janelia Fluor^® 549, free acid

Biological Activity

Application: Suitable for flow cytometry, confocal microscopy, super resolution microscopy (SRM) including dSTORM (in both live and fixed cells) and STED. Used in protocol (2017 Grimm et al - see references below) for the synthesis of Janelia Fluor^® HaloTag^® and SNAP-tag^® ligands. Cell permeable.

Properties and Photophysical Data: Excitation and emission maxima (λ) are 549 nm and 571 nm, respectively; quantum yield = 0.88; extinction coefficient = 101,000 M^-1cm^-1, A280 correction factor = 0.169; lactone-zwitterion equilibrium constant (K_L-Z) = 3.5.

Janelia Fluor is a registered trademark of Howard Hughes Medical Institute.

HaloTag is a trademark of Promega Corporation, and SNAP-tag is a trademark of New England BioLabs, Inc.

Optical Data for Janelia Fluor^® 549, free acid

Emission Color	Yellow
Brightness
λabs	549 nm
λem	571 nm
Extinction Coefficient (ε)	101,000 M-1cm-1
Quantum Yield (φ)	0.88
Closest Laser line	532 nm
Reactive Group	Free acid
Cell Permeable	Yes
Correction Factor 280	0.169
Application	Confocal Microscopy, dSTORM, STED, Flow Cytometry, Live-cell Imaging
Alternative For	Alexa Fluor® 546, Alexa Fluor® 555, BDY TMR-X, Atto 550, CF 555, TAMRA, Cyanine 3

Technical Data

The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis.
Tocris products are intended for laboratory research use only, unless stated otherwise.

Additional Information

Background References

1. A general method to improve fluorophores for live-cell and single-molecule microscopy.
   Grimm et al.
   Nat.Methods, 2015;12:244
2. Synthesis of Janelia Fluor HaloTag and SNAP-Tag Ligands and Their Use in Cellular Imaging Experiments.
   Grimm et al.
   Methods Mol.Biol., 2017;1663:179
3. Rational design of fluorogenic and spontaneously blinking labels for super-resolution imaging.
   Zheng et al.
   ACS Cent.Sci., 2019;5:1602

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