Invitrogen™ Cholera Toxin Subunit B (Recombinant) Conjugate

Catalog No.	Conjugate	Quantity
C34776	Alexa Fluor 555	100 μg
C22841	Alexa Fluor 488	500 μg
C22843	Alexa Fluor 555	500 μg
C34777	Alexa Fluor 594	100 μg
C22842	Alexa Fluor 594	500 μg
C34778	Alexa Fluor 647	100 μg
C34779	Biotin	100 μg
C34780	HRP (Horseradish Peroxidase)	100 μg
C34775	Alexa Fluor 488	100 μg

Catalog No. C34776 Supplier Invitrogen™ Supplier No. C34776

Description

Recombinant cholera toxin B subunit (CT-B) conjugates bind with high affinity to GM1 ganglioside and support neuronal tracing, GM1 labeling, membrane trafficking, and membrane organization studies. Choose from Alexa Fluor™ 488, 555, 594, and 647 fluorescent conjugates, Biotin-XX, or horseradish peroxidase (HRP) to match your detection workflow.

Recombinant cholera toxin B conjugates for GM1 labeling and neuronal tracing

Cholera toxin B subunit (CT-B) binds with high affinity to GM1 ganglioside on the cell surface and is widely used for neuronal tracing, GM1 labeling, endocytosis, and membrane trafficking studies. At neutral pH, CT-B forms a pentamer with multiple GM1-binding sites, enabling multivalent interactions with GM1-containing membranes.

These conjugates are made using recombinant cholera toxin B subunit without the enzymatically active A subunit of native cholera toxin.

Why use recombinant cholera toxin B conjugates?

• Label GM1 ganglioside: Use the high-affinity interaction between CT-B and GM1 to visualize and detect GM1-associated membrane structures.
• Trace neuronal projections: Use CT-B for well-established retrograde labeling of neuronal pathways.
• Study membrane trafficking: Follow CT-B/GM1 internalization and retrograde trafficking through endosomal pathways.
• Investigate membrane organization: Label GM1 and examine GM1-associated membrane domains in lipid raft-related studies.
• Use recombinant B subunit: Study GM1 binding and trafficking with CT-B lacking the enzymatically active A subunit of native cholera toxin.
• Choose multiple detection formats: Select fluorescent Alexa Fluor™ conjugates, Biotin-XX, or HRP to match fluorescence, affinity-based, or enzyme-based detection workflows.

Choose a CT-B conjugate for your detection workflow

Select from Alexa Fluor™ 488, 555, 594, and 647 CT-B conjugates for fluorescence imaging, Biotin-XX for avidin- or streptavidin-based detection, or HRP for enzyme-based detection.

Why choose from multiple conjugates?

• Match your imaging system: Select an Alexa Fluor™ conjugate compatible with available excitation sources, emission filters, and detectors.
• Support multicolor imaging: Choose spectrally distinct Alexa Fluor™ dyes for use with other fluorescent probes, antibodies, and cellular markers.
• Enable affinity-based detection: Use Biotin-XX conjugates with avidin- or streptavidin-based detection workflows.
• Enable enzyme-based detection: Use HRP conjugates for chromogenic or chemiluminescent detection workflows.
• Use one GM1-binding probe across workflows: Apply recombinant CT-B with different labels while maintaining the same GM1-binding biological probe.

Applications of cholera toxin B conjugates

Cholera toxin B conjugates are versatile probes for neuronal tracing, GM1 ganglioside labeling, endocytosis, and membrane trafficking studies.

Use CT-B conjugates to:

• Perform neuronal tracing, including widely used retrograde labeling of neuronal projections
• Label GM1 ganglioside on cell membranes
• Visualize GM1-associated membrane domains in lipid raft-related studies
• Study CT-B/GM1 internalization and retrograde trafficking through endosomal pathways
• Perform fluorescence imaging with Alexa Fluor™ 488, 555, 594, or 647 conjugates
• Perform avidin- or streptavidin-based detection with Biotin-XX conjugates
• Perform enzyme-based detection with HRP conjugates

For Research Use Only. Not for use in diagnostic procedures.

Order Info

Shipping Condition: Room temperature

Specifications

• Quantity: 100 μg
• Conjugate: Alexa Fluor 555
• Recombinant: Recombinant
• Content And Storage: Store in freezer (-5 to -30°C) and protect from light.
• Label Type: Alexa Fluor Dyes
• Shipping Condition: Room Temperature
• Protein Form: Recombinant
• Form: Lyophilized
• Protein Subtype: Cholera Toxin
• Product Line: Alexa Fluor

Frequently Asked Questions (FAQs)

I injected a fluorescent tracer, but cannot detect it after tissue is fixed and sectioned. What am I doing wrong?

Confirm that the tracer you are using crosslinks to proteins or has a primary amine for fixation-either a hydrazide, lysine fixable dextran, or a protein conjugate.
Use aldehyde-based fixatives to cross link the amines on the tracer.
Inject a larger amount or higher concentration of the tracer. Tracers are generally injected at 1-20% concentrations (10 mg/mL or higher).
Confirm that you are using the correct fluorescent filter for detection. You can perform a spot test by pipetting a small amount of the undiluted stock solution of the tracer onto a slide, then view under the filter you are using on your microscope. This will confirm if the tracer fluorescence can be detected and the fluorescent microscope filter is working properly.
Review tissue fixation and handling procedures to confirm if any reagents or processing procedures could be affecting the tracer.

Do you have a tracer that will only transport retrograde?

Wheat germ agglutinin and cholera toxin conjugates have been used for retrograde tracing. They may have some anterograde tracing in some applications. A selection guide can be found here (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing/protein-conjugates.html).

How do I know which tracer to choose for my experiment?

Factors to consider are size of tracer, method of delivery (injection, direct application to tissue, etc.), and if the tracer needs to be fixable. Here are some links to details about the various classes of neuronal tracers we offer and how to choose between them:

Neuronal Tracing (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing.html)
Choosing a Tracer (https://www.thermofisher.com/us/en/home/references/molecular-probes-the-handbook/fluorescent-tracers-of-cell-morphology-and-fluid-flow/choosing-a-tracer.html)
Imaging Analysis (http://assets.thermofisher.com/TFS-Assets/BID/Reference-Materials/bioprobes-50-journal.pdf)

What products do you have for neuronal tracing?

Please check out this web page (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing.html) for details.

For Research Use Only. Not for use in diagnostic procedures.