Annexin V, PE, 25tests

From STEMCELL Technologies, this PE (Phycoerythrin)-conjugated reagent enables detection of early-stage apoptotic cells by flow cytometry. Annexin V belongs to the annexin family of proteins that bind to membrane phospholipids in the presence of calcium, showing high affinity for phosphatidylserine (PS) located in the inner leaflet of the plasma membrane. During early apoptosis, PS translocates to the outer leaflet of the plasma membrane, and Annexin V detects this translocation as a characteristic marker of early cell apoptosis.

The reagent is typically used alongside a viability dye such as 7-AAD (7-Aminoactinomycin D) or Propidium Iodide. Cells undergoing early apoptosis stain positive for Annexin V and negative for the viability dye, while apoptotic death or necrosis is characterized by positive staining for both Annexin V and the viability dye. For staining, 5 μL of the reagent is added to each tube of cells resuspended at 1 – 10 × 10^6 cells/mL in Annexin V Binding Buffer, followed by a 15-minute incubation at room temperature (15 – 25°C) protected from light prior to flow cytometric analysis.

Flow cytometry (FC) is both the verified and reported application. The product is stable when stored undiluted at 2 – 8°C; it should not be frozen and should be protected from prolonged exposure to light, with shelf life extending to the expiry date on the label. The preparation is a clear liquid and is not classified as a hazardous substance or mixture according to the Globally Harmonized System (GHS).