DNA extractions from deep subseafloor sediments: Novel cryogenic-mill-based procedure and comparison to existing protocols

► Cryogenic-mill was tested as a tool for the first step of DNA extraction from subsurface sediments. ► High cell lysis efficiencies using cryogenic-mill were obtained on different sediment types. ► Thirteen procedures were compared to recover DNA: chemical extractions or kits. ► Grinding at low beating rate followed by phenol-chloroform extraction results in high DNA yields. ► It provides high-quality crude extracts for direct downstream nested-PCR, from low cell numbers.