Improved Isolation Methods of HMW DNA from Plants and Animal Tissues

Traditional methods to isolate High Molecular Weight (HMW) DNA from plants typically use liquid nitrogen grinding and mortar and pestle, and usually require from 10 to 30 grams of starting material, yet the process often results in low DNA yield.

We present a new DNA isolation method using a commercially available tissue disruptor that requires significantly less starting material and provides a significant increase in yield. For plants, 0.5 to 3 grams of young leaves from dark treated seedlings are required for the starting material, yielding 1.5 to 9 micrograms of DNA (species dependent): an approximate tenfold increase in DNA yield compared to liquid nitrogen grinding methods. For animal, 5 milligrams of tissue is required for the starting material, yielding 5 to 6 micrograms of HMW DNA.

We fix the nuclei with formaldehyde, then blend using the Qiagen TissueRuptor®. Standard filtration and centrifugation steps are followed before agarose embedding. Finally, HMW DNA is obtained after a Proteinase K and β-Agarase digestion, followed by drop dialysis. This method has been successfully tried with numerous samples, such as Papaya, Tobacco, Asparagus, Goatgrass, Eucalyptus, Hummingbird (muscle), C57BL/6 mouse (spleen, liver) and Rabbit (spleen).