The DNA Fragmentation Index (DFI) test is used to determine whether the male partner has a high, fair, or poor fertility potential.

Apoptosis is a mode of programmed cellular death based on a genetic mechanism that induces a series of cellular, morphological and biochemical alterations, resulting in fragmentation of the genomic DNA. The sensitive TUNEL method is based on the detection of single and double stranded DNA breaks occurring in the early stages of apoptosis. After an enzymatic reaction, the fluorescein label incorporated at the damaged sites of DNA is visualized by fluorescence microscopy. The apoptotic sperm appear greener, while the normal non-apoptotic sperm take up more of the DAPI stain and appear blue. Partially apoptotic sperm will appear partially blue and green. This test allows the detection of apoptosis at the single cell level and may serve as an indicator for use of antioxidants prior to IVF in order to enhance the fertility potential of sperm.

https://www.fertstert.org/article/S0015-0282(19)30008-1/fulltext

The following video on Sperm Fragmentation Index was prepared as an invited commentary on the paper by Dr. Casanova on Sperm DNA Fragmentation Index in the Scientific Journal Fertility and Sterility: Casanovas A, Ribas-Maynou J, Lara-Cerrillo S, Jimenez-Macedo AR, Hortal O, Benet J, et al. Double-stranded sperm DNA damage is a cause of delay in embryo development and can impair implantation rates. Fertil Steril 2019;111:699-707.