The halo sperm test is a test for sperm DNA damage.
Sperm cell membranes and nucleoproteins are removed by chemical treatment and stained to reveal damage to sperm DNA that cannot be visually detected.
This is a test for DNA fragmentation of sperm.
DNA fragmentation means DNA damage.
Sperm cells contain genetic material (long spherical strands of DNA), but even sperm that appear normal may have damaged DNA, a condition known as DNA fragmentation.
The halo sperm test stains sperm and visually determines the presence or absence of DNA fragmentation by the staining of the sperm head. (Figure below)
A percentage of sperm with DNA fragmentation (SDF value) of less than 20% is considered normal.
Count over 500
SDF (%) = (fragmented + degenerated) ⁄ total × 100
Since fertilization of sperm with damaged DNA may affect embryonic development and viability, we recommend the "hyaluronic acid matured sperm selection method" to select good sperm during ICSI.