Annexin V, His Tag

Annexin V, His Tag is a recombinant Annexin V protein engineered with a C-terminal polyhistidine tag, enabling convenient affinity-based handling alongside established Annexin V binding workflows used to monitor phosphatidylserine exposure. In fluorescence and imaging studies, Annexin V-His tag conjugates are frequently employed as a molecular staining reagent to visualize membrane remodeling events associated with apoptosis-like phosphatidylserine exposure in cell biology experiments. The His tag also supports robust conjugation strategies and immobilization on metal-affinity surfaces for assay development and biomaterials research.

1. Phosphatidylserine Staining

Annexin V, His Tag is used as a phosphatidylserine-binding staining reagent in fluorescence microscopy and plate-based assays where researchers track membrane exposure patterns. Common workflows include labeling Annexin V-His tag with a fluorophore (or using a fluorophore-labeled Annexin V conjugate prepared from the His-tagged protein) to visualize early membrane changes in cultured cells, and to quantify signal in imaging or multiwell formats. This application is particularly relevant for cell biology groups that need a consistent, affinity-friendly protein format for downstream fluorescent conjugate preparation.

2. Flow Cytometry Apoptosis Assays

Annexin V, His Tag supports flow cytometry workflows that quantify phosphatidylserine-positive cell populations using fluorescence readouts. Researchers typically prepare fluorescent Annexin V conjugates from the His-tagged protein and combine them with standard cytometry gating strategies to distinguish stained versus unstained populations in time-course experiments. The His tag format is also convenient for reproducible reagent manufacturing in core facilities and assay development labs that require consistent conjugation and lot-to-lot handling for cytometric analysis.

3. His-Tag Immobilized Biosurfaces

Annexin V, His Tag is frequently incorporated into biomaterials and biosurface engineering workflows where immobilized Annexin V is required for controlled capture and presentation of phosphatidylserine-containing membranes or vesicles. Metal-affinity immobilization strategies leverage the polyhistidine tag to anchor the protein onto Ni2+- or Co2+-functionalized surfaces, enabling assay formats such as membrane-binding studies, surface-based binding assays, and imaging-compatible capture platforms. This use case is common in biomaterials research groups and industrial R&D teams developing standardized surface reagents for membrane interaction characterization.

4. Vesicle Binding and Uptake Studies

Annexin V, His Tag is used to label or quantify phosphatidylserine-bearing extracellular vesicles and membrane-derived particles in fluorescence-based characterization experiments. In these studies, Annexin V-His tag conjugates help researchers detect vesicle-associated phosphatidylserine by fluorescence readout, supporting comparative experiments across preparation conditions and treatment groups. The His-tagged format also aids reagent preparation for consistent labeling of vesicle samples in analytical workflows such as fluorescence microscopy of vesicle-associated signals and orthogonal fluorescence measurements in microplate assays.