Click Chemistry Reagents from LI-COR® for Biomolecule Labeling

Biomolecule labeling continues to be a cornerstone feature of many in vitro and in vivo biological experiments. Click Chemistry has recently emerged as a convenient, versatile, and reliable method for labeling a wide variety of molecules for applications ranging from biomarker isolation to assay development.
Click Chemistry Workflow
LI-COR now offers a portfolio of Click Chemistry reagents for copper-catalyzed and copper-free methods. These products offer researchers flexibility to choose the correct reagent for a diverse array of applications. LI-COR Click Chemistry reagents include IRDye® 800CW, IRDye 680RD, and IRDye 650 infrared fluorescent dyes labeled with DBCO, azide, or alkyne groups.

Click Chemistry utilizes pairs of reagents that exclusively react with each other and are effectively inert to naturally-occurring functional groups such as amines. Unlike affinity interactions such as streptavidin-biotin, Click Chemistry forges covalent bonds between the reacting partners to deliver stable bioconjugates.

Click Chemistry reactions can be categorized into two separate groups, copper-catalyzed or copper-free. Copper-catalyzed Click Chemistry is used for initiating reactions between azides and alkynes. These reactions are also known as Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC). Although they initiate and accelerate Click Reactions, copper catalysts are cytotoxic and inappropriate for use in living systems.

Watch this informative webinar on IRDye Infrared Dye Reagents for Click Chemistry.

Click Chemistry Reagents Labeled with DBCO Groups Allow for Copper-Free Biomolecule Labeling Reactions

LI-COR now offers Click Chemistry reagents for copper-catalyzed and copper-free methods. One group of products within this portfolio includes IRDye® infrared dyes labeled with DBCO groups, which can be used for copper-free methods.

The dibenzocyclooctyne group (DBCO) allows copper-free Click Chemistry to be done with live cells, whole organisms, and non-living samples. DBCO groups will preferentially and spontaneously label molecules containing azide groups (—N3). Within physiological temperature and pH ranges, the DBCO group does not react with amines or hydroxyls, which are naturally present in many biomolecules. Reaction of the DBCO group with the azide group is significantly faster than with the sulfhydryl group (—SH, thiol).
Click Chemistry Copper-Free Reaction

Click chemistry reagents with DBCO groups are available in 0.5 mg and 5 mg sizes for 3 dyes: IRDye 80CW, IRDye 680RD, and IRDye 650. IRDye 800CW DBCO also comes in a 50-mg pack size. For other sizes, contact LI-COR Custom Services.

Watch this 18-minute webinar to learn more about Click Chemistry applications and the new LI-COR® Click Chemistry reagents.

Create a Complete Molecular Imaging Workstation

pearltrilogybuildsystemCombining the Odyssey® CLx Infrared Imaging System with the Pearl® Small Animal Imaging System creates a versatile molecular imaging workstation for in vivo and in vitro imaging.

BrightSite™ Optical Imaging Agents or probes developed using IRDye® infrared dyes can be used for in vitro, in vivo, and tissue imaging. This technology offers researchers the ability to take research from the cell to the animal, all within one lab.

Odyssey CLx Infrared Imaging System Capabilities:

  • Cell-based assays (binding capacity, specificity, competition, etc.) for optical agent development
  • Histology and whole organ imaging for studying clearance and specificity
  • Simultaneous two-color detection for two targets or one target with sample normalization

Pearl Small Animal Imaging Capabilities:

Validation Workflow and Molecular Imaging WorkstationFigure 1. Validation and Use of an IRDye Fluorescent Probe. After probe labeling, in vitro cellular assays and microscopy are used to confirm specificity. The desired target is then imaged in animals. Excised organs and tissues> can be examined for more detailed localization of the probe. Animal image captured with Pearl Imaging System. A more comprehensive discussion of approaches for the development of fluorescent contrast agents has also been published. Reference: Kovar, et al. Anal Biochem 367(2007) 1-12.

Molecular imaging – achieved with near-infrared fluorescent technology from LI-COR!