title: Finding the joker among the maize endogenous reference genes for genetically modified organism (GMO) detection.
abstract: The comparison of five real-time polymerase chain reaction (PCR) methods targeted at maize ( Zea mays ) endogenous sequences is reported. PCR targets were the alcohol dehydrogenase (adh) gene for three methods and high-mobility group (hmg) gene for the other two. The five real-time PCR methods have been checked under repeatability conditions at several dilution levels on both pooled DNA template from several genetically modified (GM) maize certified reference materials (CRMs) and single CRM DNA extracts. Slopes and R(2) coefficients of all of the curves obtained from the adopted regression model were compared within the same method and among all of the five methods, and the limit of detection and limit of quantitation were analyzed for each PCR system. Furthermore, method equivalency was evaluated on the basis of the ability to estimate the target haploid genome copy number at each concentration level. Results indicated that, among the five methods tested, one of the hmg-targeted PCR systems can be considered equivalent to the others but shows the best regression parameters and a higher repeteability along the dilution range. Thereby, it is proposed as a valid module to be coupled to different event-specific real-time PCR for maize genetically modified organism (GMO) quantitation. The resulting practicability improvement on the analytical control of GMOs is discussed.
authors.affiliation: Istituto Zooprofilattico Sperimentale del Lazio e della Toscana, Biotechnology Department, National Reference Laboratory for Genetically Modified Organisms (GMO) Analysis, Rome, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Paternò
authors.forename: Ugo
authors.initials: U
authors.lastname: Marchesi
authors.forename: Francesco
authors.initials: F
authors.lastname: Gatto
authors.forename: Daniela
authors.initials: D
authors.lastname: Verginelli
authors.forename: Cinzia
authors.initials: C
authors.lastname: Quarchioni
authors.forename: Cristiana
authors.initials: C
authors.lastname: Fusco
authors.forename: Alessia
authors.initials: A
authors.lastname: Zepparoni
authors.forename: Demetrio
authors.initials: D
authors.lastname: Amaddeo
authors.forename: Ilaria
authors.initials: I
authors.lastname: Ciabatti
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics; D018628:Gene Dosage; D057230:Limit of Detection; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards*; D012015:Reference Standards; D003313:Zea mays / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D000426:Alcohol Dehydrogenase