DNA fragmentation is the separation or breaking of DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 strands into pieces. It can be intentional by laboratory personnel or the cells, or it can be spontaneous.

Intentional

Restriction digest

Restriction digest

A restriction digest is a procedure used in molecular biology to prepare DNA for analysis or other processing. It is sometimes termed DNA fragmentation...

 is the intentional laboratory breaking of DNA strands.

Apoptosis DNA fragmentation

Apoptosis DNA Fragmentation

Apoptosis DNA fragmentation is a key feature of programmed cell death and also occurs in certain stages of necrosis. Apoptosis is characterized by the activation of endogenous endonucleases with subsequent cleavage of chromatin DNA into internucleosomal fragments of 180 BP and multiples thereof.DNA...

 is a natural fragmentation that cells perform in apoptosis

Apoptosis

Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...

 (programmed cell death)

Spontaneous

Spontaneous or accidental DNA fragmentation is fragmentation that gradually accumulates in a cell. It can be measured by e.g. Comet assay

Comet assay

The Single Cell Gel Electrophoresis assay is an uncomplicated and sensitive technique for the detection of DNA damage at the level of the individual eukaryotic cell. It was first described by Singh et al. in 1988...

.

The degree of DNA fragmentation can predict outcomes for in vitro fertilization (IVF) and its expansion intracytoplasmic sperm injection

Intracytoplasmic sperm injection

Intracytoplasmic sperm injection is an in vitro fertilization procedure in which a single sperm is injected directly into an egg.-Indications:...

 (ICSI). The sperm chromatin dispersion test (SCD) and TUNEL assay

TUNEL assay

Terminal deoxynucleotidyl transferase dUTP nick end labeling is a method for detecting DNA fragmentation by labeling the terminal end of nucleic acids.- Method :...

 are both effective in detecting sperm DNA damage. Using bright-field microscopy, the SCD test appears to be more sensitive than the TUNEL assay.

Its main units of measurement

Units of measurement

A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...

is DNA fragmentation index (DFI). A DFI of 20% or more significantly reduces the success rates after ICSI.