GM1-associated membrane imaging
Observe accessible GM1 regions and use independent readouts to assess membrane organization.
AF405 familyGM1 detection · Fluorescent conjugate
AF405 CTB
Catalog no. QH-10-1002(CTB)
A cholera toxin B subunit conjugate for GM1-associated membrane distribution and trafficking studies.
Excitation400nm
Emission424nm
Binding targetGM1GM1 ganglioside
ConjugateAF405–CTB
Spectra and detection conditions ↗Preparation & storage
- Formulation
- Supplied as an aqueous solution
- Storage
- Store at 2–8°C, protect from light. Do not freeze
AF405 CTB
A cholera toxin B subunit conjugate for GM1-associated membrane distribution and trafficking studies.
CTB associates with membranes through GM1 recognition. Multivalent binding can alter GM1 clustering and membrane shape; distinguish initial binding, subsequent uptake and probe-induced changes.
AF405–CTB
GM1
GM1-associated binding
Dashed line: noncovalent binding.
Applications and samples
Uptake and trafficking
Record incubation and chase times and compare surface and intracellular signal. Neuronal tracing requires separate validation of sample and tracing conditions.
Formulation and use
This aqueous fluorescent conjugate requires no additional dye conjugation. Store at 2–8°C protected from light; do not freeze. Check the vial concentration and buffer before dilution.
AF405 CTB · Specifications
- Product name
- AF405 CTB
- Catalog no.
- QH-10-1002(CTB)
- Dye family
- AF405
- Conjugated ligand
- CTB
- Binding target
- GM1 ganglioside
- Pack sizes
- 1 mg / 5 mg / 10 mg / 25 mg / 100 mg
- Concentration and dose
- Formulation
- Supplied as an aqueous solution
- Storage
- Store at 2–8°C, protect from light. Do not freeze
- Excitation peak (catalog reference)
- 400 nm
- Emission peak (catalog reference)
- 424 nm
- Ligand name
- Cholera toxin B subunit (CTB)
- Target name
- Ganglioside GM1
- Readout
- GM1-associated fluorescence localization
Concentration, volume and optical measurements
Calculate working dilutions from the vial concentration; pack mass does not specify test count. Peak wavelengths guide initial channel selection; sample, buffer and instrument settings also affect detection.
AF405 CTB · Protocol
The following outlines assay preparation. Confirm amounts, incubation time and temperature using this product’s instructions.
Before staining
Prepared 0 / 3
Define the endpoint
Define surface GM1, intracellular trafficking or tissue localization as the endpoint and plan controls and timing accordingly.
Confirm formulation
Check concentration and buffer against this product’s documentation and titrate; do not transfer volume-based dosing from another CTB preparation.
Control binding conditions
Protect from light, record temperature and incubation time, and use the same handling sequence for comparison groups.
Record binding and trafficking separately
For tracking, acquire separate binding-endpoint and chase images; handle unbound probe according to the assay method.
Check localization and perturbation
Use independent markers and titration to check whether localization changes with probe concentration.
Assay troubleshooting
Signal becomes intracellular over time
Review chase duration and temperature to distinguish expected uptake from changes associated with sample damage.
Strong membrane puncta
Compare lower probe amounts and shorter incubations to assess clustering associated with multivalent binding.
Request product documentation
Choose a document and enter your phone and email. Include the product lot number for a CoA.
AF405 CTBQH-10-1002(CTB)
Product manual
Working solutions, assay conditions, sample requirements and storage
Certificate of analysis (CoA)
Provide the vial lot number to request the corresponding test items and results
Safety data sheet (SDS)
Formulation-specific handling, protection and disposal information
Supplementary documents
Formulation and labeling information
Concentration, buffer, preservatives, labeling density and available testing records
Application and detection information
Sample preparation, controls, assay guidance and troubleshooting
Batch quality
Catalog specifications identify the product. Purity, component analysis, test methods and acceptance criteria are supplied in the lot-matched CoA. Include the vial lot number when requesting the report above.
Information for technical support
Include sample type, live or fixed state, buffer, instrument and channels, existing controls and the question to resolve.
Technical articles
Labeling guide
Read guide →CTB signal and lipid raft interpretation
CTB fluorescence reports GM1-associated distribution; puncta alone do not establish native lipid-raft structure.
Labeling guide
Read guide →Time-course analysis of CTB binding and uptake
Distinguish peripheral and intracellular CTB signals over time; one endpoint cannot establish a trafficking route.
Labeling guide
Read guide →CTB suitability for neuronal tracing
Check conjugate-specific application data, tissue background and detection windows before assuming tracing suitability.
Spectra & detection
Read article →AF405 spectra and detection channels
Read the bandpass wavelength range and use single-stain controls to check spillover.
References
References on reaction chemistry, ligand recognition and assay interpretation. Reagents and conditions belong to each study; these papers do not validate Qihe AF product performance or establish equivalence to Alexa Fluor products.
Structured clustering of the glycosphingolipid GM1 is required for membrane curvature induced by cholera toxin
Kabbani AM, Raghunathan K, Lencer WI, Kenworthy AK, Kelly CV. · PNAS · 117(26):14978–14986 · 2020
Examines how multivalent CTB binding affects GM1 organization and membrane shape, highlighting probe-induced perturbation.
FAQ
Does CTB positivity mean lipid-raft positivity?
CTB reports GM1-associated signal. Membrane-domain conclusions require independent evidence and assessment of probe perturbation.
Can the same amount be used for every CTB preparation?
Concentration, labeling density and sample conditions can differ. Check product documentation and titrate amount and time.
Can it be used directly for neuronal tracing?
Neuronal tracing is an application of CTB methods; suitability of this product for a specific model requires documentation and pilot validation.
How should I store it? Can I freeze it?
Store at 2–8°C, protect from light. Do not freeze. Consult the instructions for the storage duration of diluted working solutions.
How can I confirm concentration, labeling density and lot quality?
Use the vial label and formulation document for concentration, and the lot-matched CoA for labeling density and test results.
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