Coumarins are small molecular weight, water soluble, UV-excitable, blue fluorescent dyes (emission range ~410 to 470 nm). They can be either cell permeable or cell impermeant depending on their structure; the more charged moieties that are on the dye he less cell permeable the molecule is. 7‑hydroxycoumarin and derivatives are also referred in the literature as umbelliferones or umbelliferyls.
Coumarin dyes are often used to provide contrast in multicolor applications, but because coumarin fluorescence may not be as bright as that of other dyes or may be obscured by autofluorescence, they are only recommended for use with highly abundant targets or in cell tracking applications.
Coumarin derivatives (e.g., MUG, MUP, DiFMUP) are extensively used as substrates for detecting enzymatic activity in cells, homogenates, and solution.
We offer a range of coumarin-based reagents as well as high-performance fluorophores with improved characteristics for labeling and detection.
Coumarin and coumarin derivatives dashboard
 Initial brightness | Coumarin and its derivatives are traditional blue-fluorescent labels and are most commonly used as fluorogenic enzyme substrates. | ||
 Photostability in buffer | |||
 Photostability in antifade |
| 405 | DAPI | 387 | 470 | ||
 Laser line |  Common filter set |  Excitation max |
Coumarin products
We have developed a broad range of coumarin products.
Fluorescence reference standards:
- 7-hydroxycoumarin-3-carboxylic acid
- 6,8-difluoro-7-hydroxy- 4-methylcoumarin (DiFMU)
- 7-amino-4-methylcoumarin
Enzyme substrates and assays:
Rat basophilic leukemia (RBL) cells labeled in suspension with various Invitrogen CellTracker dyes. Rat basophilic leukemia (RBL) cells labeled in suspension with Invitrogen CellTracker Blue CMAC, CellTracker Green CMFDA or CellTracker Orange CMTMR prior to plating. The image was acquired using optical filter sets appropriate for DAPI, fluorescein and the Invitrogen Texas Red dye.
Coumarin reactive dyes
Select dye-labeling chemistries for conjugation with the following reactive groups:
| Amine | Thiol |
|---|---|
High-performance alternatives to coumarins
You have a choice when it comes to labeling with blue-fluorescent dye conjugates.
Imaging applications
For imaging applications, the Invitrogen Alexa Fluor 350 dye is spectrally identical to coumarin with improved characteristics for labeling and detection.
Alexa Fluor dyes
Invitrogen Alexa Fluor dyes are among the most trusted fluorescent dyes available today. In addition to superior performance, you’ll get an experienced, problem-solving technical support team, >50,000 published references, application and experimental tips, as well as protocols to help with experiment planning. For an outstanding research experience, choose Alexa Fluor dyes.
Learn more about the:
Flow cytometry applications
For flow cytometry, Invitrogen Pacific Blue dye is a high-performance blue label that is ideally suited to the 405 nm violet laser.
Violet laser–compatible antibody conjugates
We offer Invitrogen Pacific Blue, Pacific Green and Pacific Orange dyes as well as Invitrogen Qdot labels for use with the violet laser. In addition to primary and secondary antibody conjugates of these dyes, we’ve developed kits for cell proliferation, immunophenotyping, dead-cell discrimination, apoptosis, and cell cycle analysis—all aimed at helping you maximize the data you can get from your violet laser–equipped flow cytometer.
Learn more about Cell Health and Viability Assays for Flow Cytometry
Bovine pulmonary endothelial cells. Invitrogen MitoTracker Red CMXRos, SYTO 16 nucleic acid stain, anti–bovine α-tubulin (mouse monoclonal) and Alexa Fluor 350 goat anti–mouse IgG. Bovine pulmonary endothelial cells incubated with the fixable, mitochondrion-selective MitoTracker Red CMXRos. The cells were then formaldehyde-fixed, acetone-permeabilized and counterstained using SYTO 16 green-fluorescent nucleic acid stain. Microtubules were labeled with mouse monoclonal anti–α-tubulin antibody and visualized with blue-fluorescent Alexa Fluor 350 goat anti–mouse IgG. The multiple-exposure image was acquired using filter sets appropriate for Invitrogen Texas Red dye, fluorescein and DAPI.