Molecular Probes™ Cholera Toxin Conjugate consists solely of the recombinant form of the B subunit. This allows us to provide a high purity product that is completely free of toxic A subunits. Cholera toxin B subunit (CT-B) attaches to cells by binding to ganglioside G_M1 and is a powerful retrograde labeling tool for neurons. This tracer has been used in a variety of applications, including tracking forebrain afferents, parabrachial area projections, and bladder wall neurons in rats. When used in neuronal tracing applications, CT-B is typically injected via pressure injection or via iontophoresis into neural tissue.

Cholera Toxin B Subunit Specifications:
• Label (excitation/emission wavelength): Alexa Fluor™ 647 (650/668 nm)
• 11.4 kDa at neutral pH The B subunit exists in the form of a 57kDa pentamer
• The lyophilized product can be dissolved and used in a buffer (such as PBS)


Researchers recently CT-B was found to be useful as a marker for lipid rafts—membrane microdomains that are abundant in cholesterol and sphingolipids and are regarded as important tools for studying cell signaling. When staining lipid rafts, cells are first incubated with fluorescein CT-B, and then anti-CT-B antibodies are added to cross-link CT-B in lipid rafts into different patches on the plasma membrane. These plaques can be easily visualized by fluorescence microscopy. In addition to individual fluorescent CT-B conjugates, we also offer products containing Alexa Fluor™ 488, Alexa Fluor™ 555 or Vybrant™ Lipid Raft Labeling Kit with detailed protocols for cell labeling and preparation of Alexa Fluor™ 594dye’s CT-B conjugate, anti–CT-B antibody, and fluorescence microscopy.

Find more information about CT-B conjugates
We offer a variety of CT-B conjugates. For more information about these tracers, see "Protein Conjugates—Section 14.7".

For scientific research use only. Not for therapeutic or diagnostic use in humans or animals.