| Cat # | Size | Price | Quantity | |
|---|---|---|---|---|
| 604201 | 25 ug | $79 | ||
| 604202 | 100 ug | $199 |
| Application | Flow Cytometry |
|---|---|
| Format | Liquid, Purified |
| Expression Host | E.coli |
| Target Name | Annexin A5 |
| Species | Human |
| Accession Number | P08758 |
| Sources | Recombinant Human Annexin A5 (Met1-Asp320) with N-His-Xa tag is expressed in E.coli system. His tag is cut by Xa after purification. |
| Molecular Weight | This protein has a predicted molecular weight of 35.9 kDa. Under DTT-reducing conditions, the protein migrates at approximately 35 kDa on SDS-PAGE. |
| Affinity Tag | None |
| Purity | >95% based on SDS-PAGE under reducing condition |
| Regulatory Status | RUO |
| Formulation | 1xPBS/0.09%NaN3 |
| Endotoxin level | Not tested |
| Protein Concentration | 25µg size is bottled at 0.2mg/mL concentration. 100 µg size is supplied at a lot-specific concentration. |
| Storage and Handling | Briefly centrifuge the vial upon receipt. An unopened vial can be stored at 4°C for up to 2 weeks, or at -20°C or below for up to six months. The protein may be further diluted to 0.1 mg/mL using 0.22 µm-filtered PBS buffer (pH 7.4). For long-term storage, the diluted stock solution should be aliquoted and stored at ≤ –70°C to minimize freeze-thaw cycles. If additional dilution is required, carrier proteins such as FBS or BSA should be added to maintain protein stability. |
| Research Areas | Apoptosis, Cell Death |
Annexin V is a calcium-dependent phospholipid-binding protein widely used as a tool to detect apoptosis. It belongs to the annexin family of proteins, which share the ability to bind negatively charged membrane phospholipids in the presence of calcium ions. Annexin V has high affinity for phosphatidylserine (PS), a phospholipid that is normally confined to the inner leaflet of the plasma membrane in healthy cells. During early apoptosis, PS becomes externalized to the outer leaflet, where Annexin V can bind, making it a sensitive marker for programmed cell death.
Structurally, Annexin V is a ~35–36 kDa protein composed of four homologous annexin repeats that form a slightly curved, disc-like structure. Each repeat contributes to calcium-binding sites that coordinate calcium ions, enabling the protein to interact with phospholipid head groups. The convex surface of Annexin V mediates membrane binding in a calcium-dependent manner, while the opposite surface remains exposed for detection when conjugated to fluorophores or other labels. Annexin V can also form two-dimensional arrays on membrane surfaces under certain conditions.
Its primary ligands are phosphatidylserine and calcium ions. In research and development, fluorescently labeled Annexin V (e.g., FITC, PE, or APC conjugates) is extensively used in flow cytometry and fluorescence microscopy to quantify apoptotic cells. It is commonly combined with viability dyes such as propidium iodide to distinguish early apoptotic, late apoptotic, and necrotic cells. Beyond apoptosis assays, Annexin V is used in drug screening, cancer biology, immunology, and toxicology studies. Its reliable and specific detection of PS exposure makes it a foundational reagent in cell death analysis and therapeutic development workflows.
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