Flow cytometry
Use untreated, induced and single-stain controls to assess PS-positive populations alongside membrane integrity.
AF488 familyPS detection · Fluorescent conjugate
AF488-Annexin V
Catalog no. QH-10-1004(Annexin V)
Detect exposed cell-surface PS and assess cell state alongside a membrane-integrity dye.
Excitation494nm
Emission517nm
Binding targetPSExposed phosphatidylserine
ConjugateAF488–Annexin V
Spectra and detection conditions ↗Preparation & storage
- Formulation
- Supplied as an aqueous solution
- Storage
- Store at 2–8°C, protect from light. Do not freeze
AF488-Annexin V
Detect exposed cell-surface PS and assess cell state alongside a membrane-integrity dye.
Annexin V binds PS in a Ca²⁺-dependent manner. Damaged membranes can expose inner-leaflet PS to the probe, so record membrane integrity and sample handling together.
AF488–Annexin V
PS
Ca²⁺-dependent binding
Dashed line: noncovalent binding.
Applications and samples
Fluorescence microscopy
Observe surface-associated signal with matched acquisition settings and record the interval between treatment and imaging.
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.
AF488-Annexin V · Specifications
- Product name
- AF488-Annexin V
- Catalog no.
- QH-10-1004(Annexin V)
- Dye family
- AF488
- Conjugated ligand
- Annexin V
- Binding target
- Exposed phosphatidylserine
- 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)
- 494 nm
- Emission peak (catalog reference)
- 517 nm
- Ligand name
- Annexin V
- Binding mode
- Ca²⁺-dependent noncovalent binding
- Readout
- Cell-surface PS exposure, assessed alongside membrane integrity
- Buffer compatibility
- Calcium-containing binding buffer; chelators such as EDTA interfere with binding
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.
AF488-Annexin V · Protocol
The following outlines assay preparation. Confirm amounts, incubation time and temperature using this product’s instructions.
Before staining
Prepared 0 / 3
Review reagent and assay conditions
Confirm concentration, binding buffer and working amount for this SKU; record cell type, treatment duration and cell count.
Collect samples gently
Minimize damage during detachment, handling and washing. Retain the cell populations relevant to the experimental question.
Set up staining and controls
Use a suitable calcium-containing binding buffer. Titrate following this product’s instructions, protect from light and handle groups consistently.
Include membrane integrity
Choose PI, 7-AAD or another suitable dye compatible with the AF channel and follow its staining sequence.
Acquire promptly and interpret
Record acquisition delay, compensation or unmixing settings and gating order. Interpret population changes with the time point and independent cell-death measures.
Assay troubleshooting
High signal in untreated cells
Check collection damage, cell density, culture condition and acquisition delay before comparing reagent amounts.
Weak expected positive signal
Review calcium, chelator carryover, induction conditions and channel settings; check the assay with a known responsive sample.
Request product documentation
Choose a document and enter your phone and email. Include the product lot number for a CoA.
AF488-Annexin VQH-10-1004(Annexin V)
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 →Ca²⁺ and EDTA in Annexin V binding buffer
Annexin V binding requires Ca²⁺; residual EDTA or other chelators can reduce signal.
Labeling guide
Read guide →Interpretation of Annexin V positivity
Annexin V positivity indicates accessible PS. Interpret it with membrane integrity and other apoptosis markers.
Labeling guide
Read guide →Effects of cell collection on Annexin V detection
Discarding detached cells or varying collection times can change the observed Annexin V-positive fraction.
Spectra & detection
Read article →AF488 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.
A novel assay for apoptosis: flow cytometric detection of phosphatidylserine expression on early apoptotic cells using fluorescein labelled Annexin V
Vermes I, Haanen C, Steffens-Nakken H, Reutelingsperger C. · Journal of Immunological Methods · 184(1):39–51 · 1995
Introduces fluorescence detection of exposed PS with Annexin V and informs interpretation alongside membrane integrity.
FAQ
Does Annexin V positivity prove apoptosis?
Interpret exposed PS with membrane integrity, timing and independent readouts; one positive marker does not establish the death mechanism.
Can I fix and permeabilize before staining?
Fixation or permeabilization changes PS accessibility in live-cell exposure assays. Use a specifically validated workflow if fixation is required.
Is there a universal dilution?
The amount depends on lot concentration, cell count and method. Obtain this product’s instructions and perform a titration.
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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