Application of bioengineering to disease diagnosis

Traditional approaches to diagnosing disease include clinical observations, pathological changes in tissues, and searches for the etiology, by isolation, or identification of microorganisms, or by serological methods. Development of techniques for studying the molecular biology of microorganisms, manipulation of cellular systems, and improved immunoassays have contributed to better diagnostic technology. Recombinant DNA technology has made it possible to apply highly specific probes consisting of nucleotide sequences that hybridize with complementary sequences of microorganisms. The specific techniques utilized include Southern, northern, and dot blot hybridization and in situ hybridization. Identification of proteins of microorganisms is done by western blot, dot blot, and in situ peroxidase-antiperoxidase techniques. These techniques have the promise of being highly specific and rapid methods for diagnosis of disease.