title: Evaluation of four different DNA extraction methods in coagulase-negative staphylococci clinical isolates.
abstract: Currently there are several methods to extract bacterial DNA based on different principles. However, the amount and the quality of the DNA obtained by each one of those methods is highly variable and microorganism dependent, as illustrated by coagulase-negative staphylococci (CoNS) which have a thick cell wall that is difficult to lyse. This study was designed to compare the quality and the amount of CoNS DNA, extracted by four different techniques: two in-house protocols and two commercial kits. DNA amount and quality determination was performed through spectrophotometry. The extracted DNA was also analyzed using agarose gel electrophoresis and by PCR. 267 isolates of CoNS were used in this study. The column method and thermal lyses showed better results with regard to DNA quality (mean ratio of A260/280 = 1.95) and average concentration of DNA (), respectively. All four methods tested provided appropriate DNA for PCR amplification, but with different yields. DNA quality is important since it allows the application of a large number of molecular biology techniques, and also it's storage for a longer period of time. In this sense the extraction method based on an extraction column presented the best results for CoNS.
authors.affiliation: Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA).
authors.forename: Caio Fernando de
authors.initials: CF
authors.lastname: Oliveira
authors.affiliation: Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA).
authors.forename: Thiago Galvão da Silva
authors.initials: TG
authors.lastname: Paim
authors.affiliation: Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA).
authors.forename: Keli Cristine
authors.initials: KC
authors.lastname: Reiter
authors.affiliation: Laboratory of Biotechnology and Genetic, Universidade de Santa Cruz do Sul (UNISC), Laboratory of Biotechnology and Genetic, Universidade de Santa Cruz do Sul (UNISC).
authors.forename: Alexandre
authors.initials: A
authors.lastname: Rieger
authors.affiliation: Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Health Sciences Post-graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA).
authors.forename: Pedro Alves
authors.initials: PA
authors.lastname: D'Azevedo
mesh_terms: D015373:Bacterial Typing Techniques; D003030:Coagulase; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification*; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000379:methods*; D013210:Staphylococcus / Q000145:classification / Q000201:enzymology* / Q000235:genetics*
chemical_list: D003030:Coagulase; D004269:DNA, Bacterial