I have tried using PowerSoil Pro kit from Qiagen with slight modifications- incubating at 65 degree for 10 mins after adding solution CD1, increasing the number of washes with CD5 to 3 times and drying the tube for 15mins after washing.
Giorgia Pertile yes I have tried Promega, HiMedia and PCI extraction also, I also tried crushing the soil in liquid N2 for cell lysis before proceeding with extraction. Kindly suggest what else can I do.
Do you try the FastDNA spin kit for feces? We use this kit to make the DNA extraction for soil and we use the DNA for PCR, Sanger sequencing, qPCR and MiSeq analysis.