Fluorescent Annexin V
Fluorescent Annexin V - Related Videos
09:09
Annexin V and Propidium Iodide Labeling
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2023
Staining with annexin V and propidium iodide (PI) provides researchers with a way to identify different types of cell death—either necrosis or apoptosis. This technique relies on two components. The first, annexin V, is a protein that binds certain phospholipids called phosphatidylserines, which normally occur only in the inner, cytoplasm-facing leaflet of a cell’s membrane, but become “flipped” to the outer leaflet during the early stages of apoptosis. The second component is the DNA-binding...
04:21
Annexin V Binding Assay: A Fluorescence-Based Technique to Identify Apoptotic Erythrocytes via Phosphatidylserine Labeling
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2025
In this video, we demonstrate the Annexin V binding assay to measure the degree of eryptosis, erythrocyte programmed cell death, using fluorescent Annexin V staining. Apoptotic erythrocytes demonstrate phosphatidylserine translocation from the inner to the outer leaflet of the cell membrane, causing the fluorophore-tagged Annexin V to bind to the translocated phosphatidylserine, thereby emitting a fluorescent signal.
07:34
Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death
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Cited by 543 •
2011
An accurate method for the assessment of cell death is described. The protocol improves upon conventional Annexin V/ propidium iodide (PI) protocols, which display up to 40% false- positive events in cell lines and primary cells from a broad range of animal models.
07:11
Dissipative Microgravimetry to Study the Binding Dynamics of the Phospholipid Binding Protein Annexin A2 to Solid-supported Lipid Bilayers Using a Quartz Resonator
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Cited by 5 •
2018
Here, we present an experimental protocol that can be employed to determine the binding affinities and mode of interaction of label-free phospholipid-binding protein annexin A2 with immobilized solid-supported bilayers (SLB) by simultaneously measuring the mass uptake and the viscoelastic properties of the protein annexin A2.
09:00
Fluorescent in situ Hybridization on Mitotic Chromosomes of Mosquitoes
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Cited by 45 •
2012
Among the three mosquito genera, namely Anopheles, Aedes, and Culex, physical genome mapping techniques were established only for Anopheles, whose members possess readable polytene chromosomes. For the genera of Aedes and Culex, however, cytogenetic mapping remains challenging because of the poor quality of polytene chromosomes. Here we present a universal protocol for obtaining high-quality preparations of mitotic chromosomes and an optimized FISH protocol for all three genera of mosquitoes.
FAQs
Calcium ions enable Annexin V to bind phosphatidylserine with high affinity. This dependence makes the fluorescent signal reflect the availability of phosphatidylserine on the cell surface under appropriate calcium-containing conditions. Without that interaction, the probe cannot reliably indicate membrane changes associated with programmed cell death, so calcium is a critical component of the detection mechanism.
Phosphatidylserine normally resides on the inner membrane leaflet, limiting Annexin V access. During early programmed cell death, it becomes exposed on the outer surface, allowing probe binding and fluorescence. The resulting signal therefore reports a membrane-state change associated with apoptosis rather than simply measuring cell number, morphology, or general fluorescence.
Fluorescence microscopy reveals where labeled Annexin V associates with individual cells and can show cell-level visual patterns. Flow cytometry measures fluorescence across many cells, supporting broader assessment of population-level differences in phosphatidylserine exposure. The choice depends on whether the experiment prioritizes visual localization or comparative analysis of cell populations.
A membrane-impermeable dye adds a second readout of cell-membrane status to the phosphatidylserine signal. Combining both measurements helps distinguish viable, apoptotic, and necrotic cells more effectively than Annexin V fluorescence alone. This paired approach is especially useful when an experiment must separate early cell-death changes from later or more severe loss of viability.
The technique is useful when researchers need to evaluate changes in cell death or viability after an experimental treatment. Supported applications include toxicology studies, drug-response experiments, and investigations of disease-related changes in cell viability. Measuring phosphatidylserine exposure provides a way to compare how different conditions influence apoptosis-associated membrane changes.
Fluorescent Annexin V assays can indicate the extent of phosphatidylserine exposure in cells and help classify populations according to viability or cell-death state when paired with a membrane-impermeable dye. Microscopy provides fluorescence-based cellular observations, while flow cytometry supports population measurements. These outcomes help evaluate treatment effects and characterize cell-death responses.