Fluorescence Imaging

Spectra Viewer

Use this spectra viewer to interactively view the excitation and emission spectra for our fluorescent dyes (including Janelia Fluor^®, TFAX, Cyanine and BDY dyes). Spectra for other dyes are also included for reference purposes. This is a useful tool for planning and designing experiments, particularly for assessing multiplexing options. Note: absorption spectra may be displayed instead of excitation spectra.

Characteristics of Fluorescent Dyes, Probes and Proteins

Fluorescent compounds are generally small organic molecules (although they may also be peptides or proteins) that absorb light radiation of a specific wavelength and emit radiation at a longer wavelength (lower energy). The compounds cease to emit radiation immediately, when the incident radiation stops. Fluorescent compounds have a maximum excitation and emission wavelength, measured in nanometers, and the difference between the two is known as the Stokes shift. The ratio of the number of photons emitted to the number absorbed is an indicator of the efficiency of the fluorescence process and is known as the quantum yield. How strongly a fluorescent compound absorbs radiation is known as the extinction coefficient, and links the amount of radiation of a given wavelength absorbed to the molar concentration of the compound. Another useful parameter to take into account is the lifetime, which corresponds to the average time (measured in picoseconds) that the compound spends in an excited state before emitting a photon and returning to the ground state.

Featured Fluorescent Dye and Fluorescent Probe Ranges

Janelia Fluor^® Dyes

Janelia Fluor^® (JF) dyes are bright, cell permeable and highly photostable small molecule fluorophores, which are especially well suited to live-cell imaging and super-resolution techniques. Janelia Fluor^® dyes are supplied with a choice of reactive groups including click handles (tetrazine and azide), free acid, maleimide, and NHS ester (SE), allowing for simple biomolecule conjugation (conjugation protocols available).

Janelia Fluor^® dyes are compatible with self-labeling tag systems e.g. HaloTag^® and SNAP-tag^®. These dyes can be used with conventional imaging techniques, such as confocal microscopy, IHC, ICC and flow cytometry, as well as super-resolution microscopy (SRM) techniques, including STED and dSTORM. Our range also includes the Janelia Fluor^® photoactivatable dyes that are applicable in PALM microscopy.

The Janelia Fluor^® range is ideal for multiplexing as the dyes have narrow absorption/emission spectra spanning the color spectrum from the green/yellow Janelia Fluor^® 525, to the far red Janelia Fluor^® 669.

For pre-conjugated options, we also offer Janelia Fluor^® conjugated antibodies and custom conjugation services through Novus Biologicals, our Bio-Techne sister brand.

Application of Janelia Fluor^® Dyes in Cardiac Tissue - Left - displaying collagen VI in the interstitial space between muscle cells. Labeled with a primary ab against collagen VI and a secondary ab conjugated to JF549 (#6147). Scale: 50 μm. Middle - adult pig heart tissue, 10 μm thick, labeled with abs against SERCA2ATPase, displays sarcoplasmic reticulum. Top: super-resolution image (dSTORM), bottom: diffraction limited widefield image. Scale: 200 nm. Right - Cardiomyocyte stained against α-actinin, displaying its periodic structure localised at the ends of sarcomeres (Z-discs). (left) Widefield fluorescence of JF549 (right) dSTORM super-resolution image (right). Scale: 1 μm.

All images kindly provided by Prof. Christian Soeller, University of Exeter; acquired by Alex Clowsley and Anna Meletiou

Exclusive Fluorescent Microtubule Probe

Taxol Janelia Fluor^® 646 Cat. No. 6266 is a fluorogenic microtubule probe that 'switches on' only once bound to microtubules, enabling hassle-free, no-wash experiments. Simply apply to live or fixed cells and leave to incubate for an hour before viewing on a standard confocal microscope.

Labeling cells with the Taxol Janelia Fluor^® 646 probe avoids the disruptive and time-consuming washing step required with most microtubule probes. This product is particularly beneficial for those working on cells with adhesion sensitivity, providing a convenient way to visualize cells with minimal disruption. Taxol Janelia Fluor^® 646 is also ideal for tracking microtubules in live cell experiments.

Application of Microtubule Probe Taxol Janelia Fluor^® 646 dye on COS7 cells

Application of Taxol Janelia Fluor^® 646 on COS7 cells; 3 µM Taxol Janelia Fluor^® 646 was used to label COS7 cells for one hour at 37°C. Images were taken on the Leica TCS SP8 Confocal Laser Scanning Microscope.

All images very kindly provided by Prof. Christian Soeller and his team, from the University of Exeter; acquired by Evelina Lucinskaite, Anna Meletiou and Alexander Clowsley.

DRAQ™ and CyTRAK Orange™ Fluorescent Dyes from Novus

Our sister brand Novus offers nuclear (DRAQ5™ and DRAQ7™), cytosolic (DRAQ9™) and whole cell (CyTRAK Orange™) dyes for flow cytometry, fluorescence microscopy, and high content screening. These dyes are photostable and suitable for use in live or fixed cells.

Bio-Techne Antibodies for Immunofluorescence Assays

Bio-Techne family brands R&D Systems™ and Novus Biologicals provide a comprehensive range of the highest quality antibodies to support your research. We offer portfolio of over 40,000 IHC validated antibodies covering common and niche targets.

Free Fluorescent Dyes and Probes Product Guide and other Tocris Resources

The Fluorescent Dyes and Probes Product Guide gives a comprehensive list of fluorescent dyes and probes offered by Tocris, as well as essential background on each different product type. The guide contains sections on:

• Fluorescent Dyes
• Dyes for Flow Cytometry
• Fluorescent Probes
• Anti-fade Reagents
• Bioluminescent Substrates
• Fluorogenic Dyes for Light-Up Aptamers
• Fluorescent Probes for Imaging Bacteria
• TSA Reagents for Enhancing IHC, ICC & FISH Signals

Tocris is also delighted to provide free scientific posters and reviews, all written by scientific experts in their fields. We also write and produce in-house product guides and bulletins, which give an overview of how our products are used within research including, cardiovascular, stem cells, neuroscience and cancer, among others. Please request a free copy or download a PDF today! Also check our latest blog posts following current scientific trends.