JFX Dyes

The Janelia Fluor® dyes, developed by the Lavis Lab at Janelia Research Campus, outperform other fluorophores in brightness and photostability, enabling new experiments at the frontier of life science research. Recently the Janelia Fluor® dyes themselves received an upgrade to discover that isotope effects offer additional leaps in performance.

The Lavis lab found that replacing the hydrogen (H) atoms on the N-alkyl groups of many fluorophores with deuterium (D) improves brightness and photostability with minimal effects on other features. Deuterated alkylamines exhibit higher ionization potentials relative to their hydrogen-containing analogs, suggesting that deuteration could decrease relaxation via a twisted internal charge transfer (TICT) process and therefore increase quantum yield, a key feature of high-performance dyes that drove the success of the original Janelia Fluor® compounds. Deuteration also slows unwanted photobleaching pathways, leading to improved photostability.

These deuterated analogs of the Janelia Fluor® dyes, which we have named the “JFX” dyes, have similar excitation and emission spectra to the original compounds, as shown in Figure 1. In addition, the dyes showed evidence of substantially increased brightness and photostability in single-particle tracking experiments in live cells (Figure 2).

Figure 1. Normalized absorption and emission spectra of JF549 and JFX549.

Figure 2. Brightness and photostability of JFX dyes as HaloTag® conjugates in living cells. Brightness is measured as photons/s, and photostability is measured as track length in single-molecule imaging experiments. (A) 560 nm-excited dyes: JF549, JFX549, and JFX554. (B) 640 nm-excited dyes: JF646, JFX646, and JFX650.

There are two versions of the JFX dyes in two different color channels (Figure 2). JFX549, the direct analog of the azetidine-containing JF549, is virtually identical to the parent compound but shows higher brightness. Brightness and photostability improved with deuteration of the pyrrolidine-containing JF549 analog yielding JFX554, and the same improvements on JF646 resulted from targeting deuteration to azetidine or pyrrolidine groups, yielding JFX646 and JFX650, respectively.

These dyes are useful for fluorescent labeling, imaging, and detection with 560 nm or 640 nm excitation, performing substantially better than other fluorophores available on the market.

Advantages:

• Next-generation dyes: improved brightness, longer fluorescence lifetimes, and increased photostability with similar excitation/emission profiles as the original Janelia Fluor 549 and 646 dyes.
• Available in two common excitation windows:  560 nm and 640 nm.
• Cell permeable and compatible with HaloTag® and SNAP-tag® systems for live-cell imaging and standard chemical labeling strategies such as NHS esters.

Applications:

• Intracellular labeling and single-molecule tracking experiments in live cells
• Super-resolution single-molecule localization microscopy (SMLM), including techniques such as dSTORM
• Long-duration confocal fluorescent imaging
• Other basic life science or analytical methods that rely on fluorophore labeling and/or detection.
   

Intellectual Property:
Janelia Fluor® is the subject of Certificate of Trademark Registration, Serial Number 86386733

Issued U.S. Patent No. 11,091,643 and PCT application PCT/US2019/000026

Opportunity:
These dyes and patent rights are available for Commercial Licensing.

For inquiries, please reference:
Janelia 2017-043