title: Automated genomic DNA extraction from saliva using the QIAxtractor.
abstract: BACKGROUND
  Venipuncture is an invasive procedure to obtain whole blood in order to obtain high quality and sufficient amounts of genomic DNA. Obtaining DNA from non-invasive sources is preferred by patients, medical doctors and researchers. Saliva collected with cotton swabs (Salivette) is increasingly being used to study chemical compounds, and it can also be a source of DNA. However, extracting DNA from Salivettes is very laborious and time consuming. Therefore, we developed a protocol for automated genomic DNA extraction from saliva collected in Salivette using the QIAxtractor.
  
  
  METHODS
  Saliva (0.1-2.0 mL) was collected by chewing on a Salivette for 1-2 min. A total of 70 samples, collected from healthy volunteers, were extracted with the QIAxtractor robot and a Qiagen DX reagent pack. Quantity and quality was assessed using UV spectrometry and real-time polymerase chain reaction (PCR) (substitution at position -729 in the CYP1A2 gene).
  
  
  RESULTS
  The average DNA concentration from the saliva samples was 6.0 microg/mL (95% CI 5.4-6.6 microg/mL). In 100% of the saliva samples, PCR products were detected with an average cycle threshold of 23.1 (95% CI 22.6-23.6).
  
  
  CONCLUSIONS
  DNA can be extracted in sufficient amounts from Salivette with a fully automated system with a short turnaround time. Real-time PCR can be performed with these samples.
authors.affiliation: Department of Clinical Chemistry and Hematology, Gelderse Vallei Hospital, Ede, The Netherlands. keijzerh@zgv.nl
authors.forename: Henry
authors.initials: H
authors.lastname: Keijzer
authors.forename: Silvia C
authors.initials: SC
authors.lastname: Endenburg
authors.forename: Marcel G
authors.initials: MG
authors.lastname: Smits
authors.forename: Miriam
authors.initials: M
authors.lastname: Koopmann
mesh_terms: D001331:Automation; D004247:DNA / Q000302:isolation & purification*; D015894:Genome, Human; D006801:Humans; D016133:Polymerase Chain Reaction; D011933:Reagent Kits, Diagnostic; D012463:Saliva / Q000737:chemistry*
chemical_list: D011933:Reagent Kits, Diagnostic; D004247:DNA