Description
Background information
In most normal, viable eukaryotic cells the negatively charged phospholipid phosphatidylserine (PS) is located in the cytosolic leaflet of the plasma membrane lipid bilayer1. PS redistribution from the inner to the outer leaflet is an early and widespread event during apoptosis1,2. However, in necrosis, PS becomes accessible due to the disruption of membrane integrity2. Apart from necrosis and apoptosis, PS also becomes accessible in activated platelets3, in certain cell anomalies such as sickle cell anaemia4, in erythrocyte senescence5, upon degranulation of mast cells10, and in certain stages of B cell differentiation11. PS exposure also serves as a trigger for the recognition and removal of cells by macrophages6,9.
Annexin V is a 35 kDa phospholipid-binding protein and a major cell membrane component of macrophages and other phagocytic cell types. Annexin V has a high affinity to PS in the presence of physiological concentrations of calcium (CA2+)7 and has already been used to isolate cells with exposed PS using MACS® MicroBeads.4,8
Applications
The Annexin V MicroBead Kit is used for the isolation of cells with exposed PS, including sickle cells and apoptotic cells. The Annexin V MicroBead Kit has been further applied to the purification of apoptotic and non-apoptotic neutrophils to study the intracellular signaling pathways that regulate neutrophil survival. In a study on the roles of different cytosolic phospholipase A2s in apoptosis, the Annexin V MicroBead Kit has been used for sensitive assessment of PS externalization.
Columns
For positive selection: MS, LS or XS Columns. For depletion: LD, CS or D Columns.
Overview
The Annexin V MicroBead Kit was developed for positive selection or depletion of cells based on their ability to bind Annexin V. The Annexin V MicroBead Kit includes Annexin V MicroBeads and Annexin V Binding Buffer.
