Nucleic Acid Based Detection Systems for Genetically Modified Bacteria

Monitoring techniques for genetically modified nucleic acids and organisms were developed and evaluated using modified proteinase genes from lactococci as model sytems. The methods are based on specific nucleic acid probe hybridizations and on diagnostic DNA in vitro amplifications. The polymerase chain reaction technique (PCR) based approaches as well as the probe hybridization techniques allow to detect the presence of modified nucleic acids within the sample. However, the genetically modified organisms themselves as well as lateral gene transfer can only be monitored by using the in situ colony hybridization method. The model sytems were used to analyze mixed cultures, food samples, gut contents, and feces for the presence of introduced genetically modified organisms and the fate of the modified nucleic acids.