SciELO - Scientific Electronic Library Online

 
vol.32 issue1Conversion of hydroxycinnamic acids into volatile phenols in a synthetic medium and in red wine by Dekkera bruxellensisSensory acceptability and physical stability evaluation of a prebiotic soy-based dessert developed with passion fruit juice author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Food Science and Technology

Print version ISSN 0101-2061

Abstract

BRANQUINHO, Maria Regina; FERREIRA, Renata Trotta Barroso  and  CARDARELLI-LEITE, Paola. Use of real-time PCR to evaluate two DNA extraction methods from food. Ciênc. Tecnol. Aliment. [online]. 2012, vol.32, n.1, pp.112-118.  Epub Feb 06, 2012. ISSN 0101-2061.  http://dx.doi.org/10.1590/S0101-20612012005000012.

The DNA extraction is a critical step in Genetically Modified Organisms analysis based on real-time PCR. In this study, the CTAB and DNeasy methods provided good quality and quantity of DNA from the texturized soy protein, infant formula, and soy milk samples. Concerning the Certified Reference Material consisting of 5% Roundup Ready® soybean, neither method yielded DNA of good quality. However, the dilution test applied in the CTAB extracts showed no interference of inhibitory substances. The PCR efficiencies of lectin target amplification were not statistically different, and the coefficients of correlation (R2) demonstrated high degree of correlation between the copy numbers and the threshold cycle (Ct) values. ANOVA showed suitable adjustment of the regression and absence of significant linear deviations. The efficiencies of the p35S amplification were not statistically different, and all R2 values using DNeasy extracts were above 0.98 with no significant linear deviations. Two out of three R2 values using CTAB extracts were lower than 0.98, corresponding to lower degree of correlation, and the lack-of-fit test showed significant linear deviation in one run. The comparative analysis of the Ct values for the p35S and lectin targets demonstrated no statistical significant differences between the analytical curves of each target.

Keywords : DNA extraction; genetically modified organisms; GMO; food analysis; real-time PCR; linearity.

        · abstract in Portuguese     · text in English     · English ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License