Mouse Cot‑1 DNA is genomic DNA extracted from mouse liver, with fragment sizes mainly ranging from 50 to 300 bp. It is rich in rodent‑specific repetitive DNA sequences such as B1, B2, and L1 families, and serves as a core blocking reagent for rodent‑related nucleic acid hybridization experiments. It can effectively block non‑specific hybridization in microarray screening. Moreover, it suppresses non‑specific binding of rodent repetitive DNA sequences during In situ hybridization and Southern blot mapping of rodent clones, and accurately identifies mouse clones in somatic cell hybrid libraries derived from mouse‑hamster hybrid cells. This product adopts a unique fragmentation process, ensuring that more than 50% of fragments fall within the optimal range of 50–300 bp, with a blocking efficiency of over 95%. It also features strict quality control standards and high batch‑to‑batch consistency, which significantly reduce experimental background signals and improve result accuracy. It provides reliable support for various rodent‑related experiments, including Northern hybridization and liquid-phase hybridization capture.