Automated DNA extraction from large volumes

Abstract

Automation of DNA extraction with DNA-IQ TM (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.

Forensic trace DNA: a review

“…Several DNA extraction methods utilized by forensic scientists do not recover all of the collected DNA, with losses of up to 75% occurring from Chelex and organic extraction methods [ 105 , 142 , 143 ]. Some of the loss is influenced by the substrate on which the sample is presented but the majority is due to the methodology.…”

High-efficiency automated DNA extraction method for degraded old skeletal samples

“…In such cases, it is necessary to remove relatively large tissue samples for analysis and to use 15 mL or more of lysate. Since the volume of lysate is 15 mL, more effort is required in the enrichment and purification process [2]. Our automated procedure is set up to handle a maximum of 35 mL of extraction buffer per sample.…”

Modified Practical Approach in Repeated DNA Studies of Biological Evidence of Sexual Assault

“…Various modified methods for DNA extraction (7,15,24,28) which aim to improve the quantity and quality of the extracted DnA and to minimize the loss of biological material during the separation of the male component from the female one in mixed samples (3,22), have been developed.…”