Annexin V-APC/PI Apoptosis Detection Kit - BioReagent, Biological Stain, for microscopy, Suitable for Immunofluorescence(IF), high purity

Cat. No.: A1372287

GRADE & PURITY BioReagent, Biological Stain, for Microscopy, Suitable for Immunofluorescence(IF)

Overview

  Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS). Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane. Upon initiation of apoptosis, PS loses its asymmetric distribution across the phospholipid bilayer and is translocated to the extracellular membrane leaflet marking cells as targets of phagocytosis. Once on the outer surface of the membrane, PS can be detected by fluorescently labeled Annexin V in a calcium-dependent manner.

  In early-stage apoptosis, the plasma membrane excludes viability dyes such as propidium iodide (PI), 7-AAD. These cells will stain with Annexin V but not a viability dye, thus distinguishing cells in early apoptosis. However, in late stage apoptosis, the cell membrane loses integrity thereby allowing Annexin V to also access PS in the interior of the cell. A viability dye can be used to resolve these late-stage apoptotic and necrotic cells (Annexin V, viability dye-positive) from the early-stage apoptotic cells (Annexin V positive, viability dye-negative).

  This kit is suitable for the identification and enumeration of dead cells, such as apoptotic or necrotic cells, by flow cytometry.

A1372287	Components	20T	50T	100T	Storage	Quantity Per Test
A1372287A	10X Annexin V Binding Buffer	5 mL	10 mL	20 mL	2-8℃	200 μL per 0.5–1.0 × 10⁵ cells.
A1372287B	Annexin V (APC)	100 μL	250 μL	500 μL	2-8℃. Store in the dark.	5 μL per 0.5–1.0 × 10⁵ cells.
A1372287C	Propidium iodide Staining Solution (PI)	100 μL	250 μL	500 μL	2-8℃. Store in the dark.	2 μL per 0.5–1.0 × 10⁵ cells.

Note: The recommended number of cells to stain per test is 0.5–1.0 × 10⁵ cells.

Instruction for use

1. Dilute 10X Binding Buffer to 1X using distilled water (1 mL 10X Binding Buffer + 9 mL ddH2O).

2. Wash cells twice with cold PBS and then resuspend the desired amount of cells in Annexin V Binding Buffer at a concentration of 0.5–1.0×10⁶/mL.

3. Add 5 µl of FITC Annexin V and 2 µl PI to 100 µL of the cell suspension

4. Gently vortex the cells and incubate for 10 min at RT (25°C) in the dark.

5. Add 100 µl of 1X Binding Buffer to each assay. Analyze by flow cytometry within 1 hr.

Storage and Shipping

Storage

Store at 2-8°C,Protected from light,Do not freeze

Shipped In

Wet ice,Do not freeze

Stability And Storage

Store at 2-8°C long term (12 months). Store in the dark. Do not freeze.

Images

Flow Cytometry: Annexin V-APC/PI Apoptosis Detection Kit (A1372287)

Annexin V-APC/PI Apoptosis Detection Kit (A1372287) - Flow Cytometry
Flow cytometric analysis of U937 cells untreated (left) or treated with 4µM camptothecin (C111281) for 4 hours using Annexin V-APC/PI Apoptosis Detection Kit (A1372287).

Untreated cells were primarily Annexin V-APC and PI negative, indicating that they were viable and not undergoing apoptosis. After a 4 hour treatment (right panels), there were primarily two populations of cells: Cells that were viable and not undergoing apoptosis (Annexin V-APC and PI negative) and cells undergoing apoptosis (Annexin V-APC positive and PI negative). A minor population of cells were observed to be Annexin V-APC and PI positive, indicating that they were in end stage apoptosis or already dead.

References

1. Jiao Sun, Yiqing Wang, Jiaxing Zhang, Jianhao Wang, Cheng Wang.  (2025)  A drug reservoir strategy for long-acting cancer therapy using morphologically transformed amphiphilic polymeric nanoparticles.  Acta Biomaterialia,      [PMID:40617494] [10.1016/j.actbio.2025.07.006]