1. Apoptotic cells changes the structure of their membrane, which leads to the exposure of Phosphatidylserine on the membrane surface.
2. The redistribution of phosphatidylserin from internal to external membrane surface for recognition by phagocytes is an early indicator of Apoptosis.
3. Annexins are ubiquitous homologous proteins that bind phospholipids in presence of calcium.
Principle of the device
1. Annexin V is used as an apoptotic sperm marker and it is conjugated with paramagnetic beads.
2. Annexin V binds specifically binds to phosphatidylserine (on the surface of apoptotic sperms) and these Annexin bound sperms when pass through the magnetic field they stick to the magnetic column
3. And the sperms which are free from Annexin i.e. non apoptotic sperms will get collected in the collection tube.
Indications for doing MACS
1. Multiple failure, attempt > 2
2. High sperm dfi.
3. Frozen sample used for ICSI
5. Paternal age > 50 years.