Identification of PCR-amplified genetically modified organisms (GMOs) DNA by peptide nucleic acid (PNA) probes in anion-exchange chromatographic analysis.
PCR products obtained by selective amplification of transgenic DNA derived from food samples containing Roundup Ready soybean or Bt-176 maize have been analyzed by anion-exchange HPLC. Peptide nucleic acids (PNAs), oligonucleotide analogues known to bind to complementary single-stranded DNA with high affinity and specificity, have been used as specific probes in order to assess the identity of the peaks observed. Two different protocols were adopted in order to obtain single-stranded DNA: amplification with an excess of one primer or digestion of one DNA strand. The single-stranded DNA was mixed with the PNA probe, and the presence of a specific sequence was revealed through detection of the corresponding PNA:DNA peak with significantly different retention time. Advantages and limits of this approach are discussed. The method was tested with reference materials and subsequently applied to commercial samples.
Rossi
Stefano
S
Dipartimento di Chimica Organica e Industriale Università di Parma, Viale G. P. Usberti 17/A, I-43100 Parma, Italy.
Lesignoli
Francesca
F
Germini
Andrea
A
Faccini
Andrea
A
Sforza
Stefano
S
Corradini
Roberto
R
Marchelli
Rosangela
R
D000838:Anions; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004247:DNA / Q000032:analysis*; D015341:Nucleic Acid Probes; D030821:Plants, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013025:Glycine max / Q000235:genetics; D003313:Zea mays / Q000235:genetics
D000838:Anions; D015341:Nucleic Acid Probes; D004247:DNA