Cholera Toxin Subunit B (Recombinant), Alexa Fluor™ 488 Conjugate
Cholera Toxin Subunit B (Recombinant), Alexa Fluor™ 488 Conjugate
Invitrogen™

Cholera Toxin Subunit B (Recombinant), Alexa Fluor™ 488 Conjugate

Molecular Probes™ cholera toxin conjugates are made from a recombinant version of the B subunit only. This allows us toRead more
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Catalog NumberQuantity
C34775100μg
C22841500μg
Catalog number C34775
Price (USD)
328.00
Each
Add to cart
Quantity:
100μg
Price (USD)
328.00
Each
Add to cart
Molecular Probes™ cholera toxin conjugates are made from a recombinant version of the B subunit only. This allows us to provide a very high-purity product that is completely free of the toxic A subunit. Cholera toxin B subunit (CT-B) attaches to cells by binding to ganglioside GM1, making it a powerful tool for retrograde labeling of neurons. This tracer has been used in a variety of applications, including tracing of rat forebrain afferents, projections of the parabrachial region, and neurons of the urinary bladder wall. When used in neuronal tracing applications, CT-B is typically introduced by pressure injection or by iontophoretic injection into neural tissue.

Cholera Toxin Subunit B Specifications:
• Label (Ex/Em): Alexa Fluor™ 488 (495/519 nm)
• At neutral pH, the 11.4 kDa B subunit exists as a 57 kDa pentamer
• Lyophilized product can be dissolved in buffer (e.g., PBS) for use


Cholera Toxin Subunit B for Studying Lipid Rafts
More recently, researchers have found that CT-B can be used as a marker for lipid rafts, which are membrane microdomains enriched in cholesterol and sphingolipids thought to be important in cell signaling. For lipid raft staining, cells are first incubated with fluorescent CT-B. Then, an anti–CT-B antibody is added to crosslink the CT-B in the lipid rafts into distinct patches on the plasma membrane. These patches are easily visualized by fluorescence microscopy. In addition to individual fluorescent CT-B conjugates, we also offer Vybrant™ Lipid Raft Labeling Kits that contain the Alexa Fluor™ 488, Alexa Fluor™ 555, or Alexa Fluor™ 594 dye conjugates of CT-B, an anti–CT-B antibody, and a detailed protocol for labeling and preparing cells for fluorescence microscopy.

Find More CT-B Conjugates
We offer various CT-B conjugates. Review Protein Conjugates—Section 14.7 in the Molecular Probes™ Handbook for more information on these tracers.

For Research Use Only. Not for human or animal therapeutic or diagnostic use.
For Research Use Only. Not for use in diagnostic procedures.
Specifications
Quantity100μg
ConjugateAlexa Fluor 488
RecombinantRecombinant
Label TypeAlexa Fluor Dyes
Shipping ConditionRoom Temperature
Protein FormRecombinant
FormLyophilized
Protein SubtypeCholera Toxin
Product LineAlexa Fluor™
Unit SizeEach
Contents & Storage
Store in freezer (-5 to -30°C) and protect from light.

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.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

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).

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

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)

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

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.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.