www.checkbiotech.org ; www.raupp.info ; www.czu.cz

Karl-Heinz Engela and colleagues from research institutions in Germany
review methods and challenges of ?Quantification of DNA from genetically
modified organisms in composite and processed foods? in a recent issue of
Trends in Food Science and Technology, October 2006.

Legislation in the European Union requires certain thresholds for the
presence of materials derived from genetically modified organisms (GMO).
Testing for GM presence is therefore important to meet trade requirements
for certain countries.

Researchers report that:

1) Differences in particle sizes of components of food products can lead to
over and underestimation of GMO contents;

2) Qualitative assays demonstrated that longer target sequences become
increasingly susceptible to degradation, resulting in false negative results
when analyzing samples of processed foods or feeds;

3) New methods of quantification, such as ligation-dependent probe
amplification (LPA) and microarray technology, should be used so that the
effects of food composition and processing can be ruled out; and

4) Quantitative screening assays can be used in combination with synthetic
quantification standards to gain important information about the
compositions of samples.

Subscribers to the journal can read the complete article at :
[dx.doi.org]

------------------------------------------
Posted to Phorum via PhorumMail