Filtern
Dokumenttyp
- Beitrag zu einem Tagungsband (4)
- Zeitschriftenartikel (3)
- Vortrag (3)
Eingeladener Vortrag
- nein (3)
Reliable and efficient methods for detecting genetically modified organisms (GMOs) are essential for establishing an effective system for traceability all along the supply chain from seed producers to final consumers. The latter is especially meaningful in European Union and other countries where strict legislations on GMOs were set up. Performance of the methods used in laboratories around the world should be uniform, in order to obtain reliable and comparable results. Accreditation is a suitable system for harmonising procedures in each testing laboratory. In this paper, key elements for the accreditation of molecular biology methods for GMO detection according to ISO/IEC 17025 are described. The procedures described are also valuable for the accreditation of molecular methods for all laboratory diagnostics where qualitative and quantitative characterisation of nucleic acids is needed.
A procedure has been developed for the synthesis of N-cyclopentadienyl amidinium ylides of the general formula C5(CO2Me)4[ArNC(Ar')NHAr]. According to the X-ray diffraction data, 1H and 13C NMR spectroscopy, and MNDO quantum-chemical calculations, the title compounds have a zwitterionic structure with the positive charge localized over the amidine NÄCÄN triad, and the negative charge, over the cyclopentadiene fragment. The configuration of the amidine moiety is stabilized by additional interaction of the NH hydrogen atom with the negatively charged cyclopentadiene ring (-bonding). The ylides are chiral due to atropoisomerism arising from a high energy barrier (G 298 >25 kcal/mol) to rotation of the Ar' substituent about the ordinary CÄC bond in the amidinium fragment.