The kit adopts a convenient, non-toxic method for isolating/purification of genomic DNA from various animal samples, including mouse tails and various other animal tissues or cultured cells. Pure, archive-grade genomic DNA with high molecular weight will be obtained. The purified DNA is ready for a variety of applications including multiplex PCR, restriction digestion, sequencing, Southern blot and hybridization. The kit is not only applicable for various tissues, but also flexible for experimental sample sizes. The typical purified genomic DNA will be over 100-200kb in size.