USDA ARS Sunflower and Plant Biology Research Unit 1 article published in JoVE Genetics Purification of High Molecular Weight Genomic DNA from Powdery Mildew for Long-Read Sequencing Joanna M. Feehan*1,2, Katherine E. Scheibel*1, Salim Bourras3, William Underwood4, Beat Keller3, Shauna C. Somerville1 1Department of Plant and Microbial Biology, University of California Berkeley, 2John Innes Centre, Norwich Research Park, 3Department of Plant and Microbial Biology, University of Zürich, 4USDA-ARS Sunflower and Plant Biology Research Unit Described here is a method for the extraction, purification, and quality control of genomic DNA from the obligate biotrophic fungal pathogen, powdery mildew, for use in long-read genome sequencing.