The principle of the polymerase chain reaction lies in multiple amplification of a certain DNA or RNA area by enzymes in laboratory conditions. This results in formation of the DNA or RNA quantity sufficient for the visual analysis. In the course of the study, only the area coming under the given conditions is to be copied and only if present in a sample being studied.

For example, the material for the study, in which the availability of the causative agent’s DNA or RNA fragments is assumed, is to be placed into a special reactor (THERMOCYCLER). Then, the specific enzymes are to be added to it which contact with the pathogen’s DNA or RNA and its copy synthesis takes place. Such copying is performed in several steps – in the ‘chain reaction’ sort – and after all, hundreds and thousands of copies may be generated from just one copy of the genetic material. After that, the analysis and comparison of the result with the existing database of various causative agents’ structure take place.

With the PCR it is not only possible to detect the causative agent type, but also to obtain the quantitative analysis result, i.e., the number of causative agents in human body.

The PCR diagnosis advantages:

• Direct detection of the causative agent’s presence (namely, the specific area of the causative agent’s DNA or RNA) in the sample being studied;
• High specificity allows for identifying a unique DNA or RNA area typical to a certain causative agent which excludes any potential PSEUDOREACTIONS;
• High sensitivity of the PCR method allows for detecting even the occasional cells of causative agents (viruses, bacteria);
• Development of the versatile PCR methods to detect various causative agents. This methodology allows for detecting several causative agents from one bioassay test;
• Quick analysis result obtaining.