Cell Apoptosis Assay Services

Apoptosis, or programmed cell death, is essential for maintaining cellular homeostasis and preventing disease development, including cancer. Measuring apoptosis supports cancer biology, drug development, and toxicology research. ICE Bioscience provides precise and reliable apoptosis analysis through Annexin V staining and Caspase 3/7 activity assays.

Annexin V staining is widely used to detect early apoptosis by measuring the translocation of phosphatidylserine (PS) from the inner leaflet of the plasma membrane to the outer leaflet.

Principle: In healthy cells, PS is located on the cytoplasmic side of the plasma membrane. During early apoptosis, PS becomes exposed on the outer membrane surface, where it binds Annexin V with high affinity. Annexin V binding can be detected by flow cytometry to identify apoptotic cells.

Dual Staining: Propidium Iodide (PI) can be used together with Annexin V to distinguish apoptotic and necrotic cells. PI enters cells with compromised membranes, which are typically in late apoptosis or necrosis. Annexin V⁺/PI⁻ cells are classified as early apoptotic, whereas Annexin V⁺/PI⁺ cells represent late apoptotic or necrotic populations.

The Caspase 3/7 Activity Assay detects the activity of caspase-3 and caspase-7, key executioner enzymes in apoptosis. These caspases cleave cellular substrates during the systematic breakdown of cellular components, including DNA fragmentation and nuclear condensation.

Principle: Once apoptosis is initiated, caspase-3 and caspase-7 become activated and cleave specific luminescent or fluorescent substrates. The resulting detectable signal is proportional to caspase activity and the level of apoptosis in the cell population.

Execution-Phase Detection: Unlike Annexin V, which primarily identifies early apoptosis, the Caspase 3/7 Assay focuses on the execution phase and provides information about later stages of the apoptotic process.