title: Comparison of commercial DNA preparation kits for the detection of Brucellae in tissue using quantitative real-time PCR.
abstract: BACKGROUND
  The detection of Brucellae in tissue specimens using PCR assays is difficult because the amount of bacteria is usually low. Therefore, optimised DNA extraction methods are critical. The aim of this study was to assess the performance of commercial kits for the extraction of Brucella DNA.
  
  
  METHODS
  Five kits were evaluated using clinical specimens: QIAamp DNA Mini Kit (QIAGEN), peqGold Tissue DNA Mini Kit (PeqLab), UltraClean Tissue and Cells DNA Isolation Kit (MoBio), DNA Isolation Kit for Cells and Tissues (Roche), and NucleoSpin Tissue (Macherey-Nagel). DNA yield was determined using a quantitative real-time PCR assay targeting IS711 that included an internal amplification control.
  
  
  RESULTS
  Kits of QIAGEN and Roche provided the highest amount of DNA, Macherey-Nagel and Peqlab products were intermediate whereas MoBio yielded the lowest amount of DNA. Differences were significant (p < 0.05) and of diagnostic relevance. Sample volume, elution volume, and processing time were also compared.
  
  
  CONCLUSIONS
  We observed differences in DNA yield as high as two orders of magnitude for some samples between the best and the worst DNA extraction kits and inhibition was observed occasionally. This indicates that DNA purification may be more relevant than expected when the amount of DNA in tissue is very low.
authors.affiliation: Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Naumburgerstrasse 96a, 07743 Jena, Germany. herbert.tomaso@web.de
authors.forename: Herbert
authors.initials: H
authors.lastname: Tomaso
authors.forename: Mireille
authors.initials: M
authors.lastname: Kattar
authors.forename: Meike
authors.initials: M
authors.lastname: Eickhoff
authors.forename: Ulrich
authors.initials: U
authors.lastname: Wernery
authors.forename: Sascha
authors.initials: S
authors.lastname: Al Dahouk
authors.forename: Eberhard
authors.initials: E
authors.lastname: Straube
authors.forename: Heinrich
authors.initials: H
authors.lastname: Neubauer
authors.forename: Holger C
authors.initials: HC
authors.lastname: Scholz
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D002002:Brucella / Q000235:genetics / Q000302:isolation & purification*; D002006:Brucellosis / Q000175:diagnosis*; D004269:DNA, Bacterial / Q000302:isolation & purification*; D006801:Humans; D008967:Molecular Biology / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D004269:DNA, Bacterial
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