Automated DNA extraction from large volumes

Automation of DNA extraction with DNA-IQ™ (Promega Corporation), requires special adaptations when trace amounts of DNA must be recovered from substrates requiring large volumes of extraction buffer (e.g. clothing). We have developed a method consisting of in situ cell lysis with DNA extraction buffer (containing SDS or Sarkosyl, Proteinase K, DNA IQ lysis buffer) followed by batch DNA recovery through incubation with DNA-binding magnetic beads. Tests were performed with blood, semen, saliva and manipulated or worn objects on cotton, polyester and nylon substrates. The process was optimized for incubation time, temperature, detergent and Proteinase K concentrations. Non-probative forensic samples were tested and the procedure integrated into the robotic scripts.