Cell-Free DNA​

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Extracellular DNA was first detected in the blood of humans in 1948. cfDNA has now been detected in blood, lymph, bile, milk, urine, saliva, mucous suspension, spinal fluid, and amniotic fluid in mammals. Furthermore, extracellular DNA has been found in almost every animal and plant which has been examined for it. The amount, characteristics, and dynamics with age of cfDNA is still largely unknown. However, there is increasing evidence that the presence cannot be explained by residues of cell-death alone.