Diagnosis involves the identification of a particular phenomenon. Diagnostic products can aid in the detection and study of infectious agents. These products are employed in microbiological analyses by detecting the presence of microorganisms by applying molecular biology and biochemistry to medical testing. These diagnostic processes utilize in-vitro biological assays such as PCR-ELISA or Fluorescence in-situ hybridization. They can detect molecules often present in low concentrations, which are a marker of disease or risk, or perhaps a metabolite of the pathogen, which is present in samples taken from a patient.

 

Various methods based on nucleic acid detection require polymerase chain reaction (PCR) to vastly increase the number of nucleic acid molecules. Some diagnostic kits employ antigen-antibody reactions to detect the presence of infections. Microarray chips facilitate the testing of multiple biomarkers at once ensure proper diagnosis.