Cell‐free DNAs (cfDNAs) are DNA fragments ranged between 50-1000 bp bound to mononucleosomes, which circulate extracellularly in bloodstream. cfDNAs in plasma originate from hematopoietic cells and contain sequences of entire genomes. Given the broad range of information they provide, cfDNAs are isolated from human blood in clinical and research laboratories to study the state of health and disease of the donors. The degree of fragmentation in cfDNAs depends on several parameters such as the origin of DNA (fetal, tumor, microbial DNA), health of the donor, blood sampling procedure and handling of the sample. They can be potentially used as a non‐invasive detection method to evaluate the state and progression of the disease. Apart from their sequences, cfDNAs also carry the information regarding nucleosomal landscape of cell(s)-of-origin and the dynamics of the epigenome. ZellX^® Cell free DNA (cfDNA) isolation Kit is designed for the quick purification of DNA from fresh or frozen (EDTA or citrate) serum or plasma. It works based on the ability of DNA to bind to silica membrane in the presence of high concentrations of chaotropic salts. The cfDNA molecules bind to the silica-based membrane, and impurities such as proteins and nucleases are removed by thorough washing steps. The DNA fragments are then eluted in Elution buffer and stored at -20°C. ZellX^® Cell free DNA (cfDNA) isolation Kit uses a special columns designed for high recovery of fragmented DNA in a range of 100-1000 base pairs.