Polymerase chain reaction identifies bio-pathogens
The PCR (polymerase chain reaction) is a biotechnological method to multiply genetic material and identify specific sequences. Since the biodiversity of organisms and their products is also reflected in the genetic material, the PCR allows for a definite identification by detecting this specific DNA sequences. The PCR is one of the most sensitive methods of detection: The smallest amount of traces of the pathogens to be identified is enough for the multiplication and identification!
First, the DNA target sequences (e.g. a genetic sequence of salmonella bacteria or DNA on anthrax spores) are marked with primers. These marks allow an enzyme to dock on the target sequence and to subsequently copy it. In a temperature-controlled chain reaction, thousands of copies can thus be generated which then can be made visible via colourings. The specificity of the marker primers used and of the polymerase guarantee a definite identification of the pathogen.