Annexin V
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.
03:13
An In Vitro Assay to Assess CAR T Cell Cytotoxicity against Tumor Spheroids
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2025
This video demonstrates an in vitro assay evaluating the cytotoxic effects of CAR T cells on 3D tumor spheroids expressing fluorescent proteins. This assessment utilizes the Annexin V red fluorescent probe, which binds to exposed phosphatidylserine residues on the outer leaflet of apoptotic cancer cells after interactions with CAR T cells. The red fluorescence emitted by the probe aids in distinguishing these cells from healthy ones emitting green fluorescence.
FAQs
Calcium enables Annexin V to bind exposed phosphatidylserine on the cell surface. Without this calcium-dependent interaction, the protein cannot reliably report the membrane change associated with apoptosis. This requirement connects the probe’s biochemical behavior to assay conditions, so fluorescence should be interpreted within a calcium-supported staining system.
During apoptosis, phosphatidylserine shifts from the inner leaflet of the plasma membrane to the outer surface. Annexin V detects this redistribution rather than merely measuring whether a cell is present or intact. The resulting signal identifies a membrane-associated change linked to apoptosis, while viability-dye information helps classify the broader cell population.
A membrane-impermeant viability dye provides a second measurement alongside phosphatidylserine binding. Combining the two signals helps distinguish viable cells from cells showing apoptotic membrane changes and from necrotic populations. This paired strategy is more informative than relying on Annexin V fluorescence alone because it relates phosphatidylserine exposure to cell viability status.
The workflow uses fluorescently labeled Annexin V together with a membrane-impermeant viability dye, followed by analysis through flow cytometry or microscopy. Calcium must be present so Annexin V can bind exposed phosphatidylserine. The resulting fluorescence measurements are then used to compare cell populations according to membrane changes and viability.
Both flow cytometry and microscopy can analyze fluorescent Annexin V labeling, but they provide different ways to examine the stained material. Flow cytometry supports assessment of viable, apoptotic, and necrotic cell populations, whereas microscopy allows the labeled cells to be examined through an imaging-based readout. The choice depends on the experimental purpose.
Annexin V measurements support studies that need to track cell-death-associated membrane changes. Applications include developmental biology, disease mechanisms, toxicology, and drug evaluation. In these settings, combining phosphatidylserine detection with viability information helps researchers examine how biological conditions or treatments relate to apoptotic and necrotic cell populations.