Advances in Biological Research 10 (6): 388-397, 2016 ISSN 1992-0067 © IDOSI Publications, 2016 DOI: 10.5829/idosi.abr.2016.388.397 Corresponding Author: Mebrahtu Gebreyohannes,Faculty of Veterinary Medicine, Department of Veterinary Pharmacy and Biomedical Science, University of Gondar, Ethiopia E-mail:mebrat1986@gmail.com 388 A Brief Review on Molecular Diagnostic Tools: Principles, Application and Limitations Mamo Adane, Mebrahtu Gebreyohannes and Gebreselema Gebreyohannes 1 1 2 Faculty of Veterinary Medicine, Department of Veterinary Pharmacy and Biomedical Science, 1 University of Gondar, P.O.box;196, Gondar, Ethiopia Department of Biology, College of Natural and Computational Sciences, 2 The University of Gondar, P.O.box;196, Gondar, Ethiopia Abstract: Although the diagnosis of diseases is still primarily based on conventional methods (staining, culture, biochemical analysis), a series of advanced molecular diagnostic tools are increasingly introduced and incorporated in the workflow of clinical laboratories worldwide. These tools, such as polymerase chain reaction, northern blotting, restriction length polymorphism, flow cytometry, southern blotting, fluorescent in situ hybridization, agarose gel electrophoresis and pyrosequencing that are based on either the properties of nucleic acids (deoxyribonucleic acid and ribonucleic acid) or proteins of the target agents, have improved the efficacy, accuracy and speed of detection and identification of disease causing agents and characterization of the diversity of pathogens. They are mainly involved in medicine, ribonucleic acid analysis, criminal case determination, origin and evolution of species, deoxyribonucleic acid fingerprinting, forensic analysis, immunophenotyping, deoxyribonucleic acid studies, single nucleotide polymorphism, resequencing, tag sequencing and microbial identification. Therefore, advanced molecular diagnostic tools are new class of diagnostic tests that are used for identification of nucleic acids or proteins to test the status of infectious diseases and genetic disorders. But, they have some limitations like expensiveness, high technical need and sensitivity for even minor changes during procedures. So advanced molecular diagnostic tools have a cutting- edge role in the diagnosis of animal and human diseases and they should be implemented in different diagnostic sectors. Key words: Application Principle Advantage Disadvantage Molecular tools, INTRODUCTION animals, the requirement for strict diagnostic approaches The basis for effective treatment and cure of a patient development of new methods and techniques in the area is the rapid diagnosis of disease and its causative agent of molecular biology has gained new insights into the that is founded on the analysis of the clinical symptoms genetic and structural features of a considerable numbers coupled with laboratory tests [1]. However, in the face of of pathogens [1]. Improvements in antibiotic and antiviral current problems in laboratory tests of disease, it is therapy for specific microorganisms will also require apparent that the continued use of older and slower development of increasingly more accurate methods of methods of detection techniques is unacceptable. This is diagnosis. Advanced molecular diagnostic tools are such because of challenges with the traditional detective accurate methods of disease diagnosis [3]. Advanced techniques that include difficulty in growing of organisms molecular diagnostics tools are methods for the in prepared media or in cell culture, slow or poor growth measurement of deoxyribonucleic acid (DNA), kinetics in vitro, limited sensitivity and specificity, labor ribonucleic acid (RNA) and proteins, or other and technical expertise requirements [2]. Because of poor metabolites to detect certain genotypes, mutations, or diagnostic outcomes of traditional detective techniques biochemical changes that may be associated with certain and increasing incidence and mortality of humans and states of health or disease [4]. became a very urgent issue. As a result, the rapid