Human Cot-1 DNA is a human placental DNA with a size distribution in the range of 50-300bp. In liquid phase capture, this product is mainly used for non-specific hybridization in closed probe hybridization capture, and the closed region is repeated DNA sequences (such as Alu and Kpn family members). It can reduce the non-specific hybridization in the process of probe hybridization, improve the probe target rate and increase the capture efficiency.