الفهرس 
Introduction & Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Molecular diagnostics is one of the most recent innovations in the clinical microbiology laboratory over the past several years and is probably the fastest growing section or department in many clinical laboratories
Molecular biology techniques utilize DNA, RNA, and enzymes that interact with nucleic acids to understand biology at a molecular level.
Fluorescent in situ hybridization (FISH) is a tool that today is widely used for identification, visualization and localization of microorganisms in many fields of microbiology. Most molecular diagnostics testing procedures use the basic concept of nucleic acid hybridization. Nucleic hybridization refer to formation of hydrogen bonds between nucleotides of single stranded DNA and/or RNA molecules that are complementary to each other. This form a stable double stranded nucleic acid molecule. The resulting double stranded hybrids may be DNA:DNA; DNA:RNA, or RNA:RNA.
Several variables affect the outcome of a given hybridization reaction. These variable include; Temperature, Length of the probe, Probe Concentration, Salt concentration, PH& Probe selection .Hybridization reaction may occur in a solid support mechanism ,in situ or in solution
Amplification may be used to increase the target microorganisms nucleic acid in a sample in a short amount of time this increase of the nucleic acid can be detected by various methods .
Amplification have many advantages and rapid detection with high sensitivity high specificity PCR assays rapidly and precisely detects the presence of microorganisms, including those that are fastidious and slow growing, directly from clinical specimens.
In PCR, DNA is amplified in a thermocycler by repeating the three major steps: denaturation of DNA template into ssDNA, annealing of oligo nucleotide primers to their complementary targets, and extension of the primers by DNA polymerase to generate a copy of the target gene Advantages of PCR: High sensitivity High specificity Good reproducibility Limitations of PCR: false-positive test results& false-negative test results
In conclusion, molecular diagnostic techniques have a significant role to play in clinical bacteriology, although their adoption will never replace conventional methodologies, which continue to be the cornerstone of modern bacteriological methods. Indeed, such molecular diagnostic assays may only be implemented in specialized laboratories to enhance laboratory diagnostic efficiency, where the use of such assays will be mainly confined to diagnosis, identification and genotyping, where current conventional approaches are grossly inadequate. Adoption of such methods in bacteriology has occurred at a much slower rate than in clinical virology, where the inadequacies of conventional virology, has accelerated the adoption of molecular methods. Integration of molecular approaches in clinical bacteriology will be enhanced through the production of a greater range of diagnostic kits, as well as the existence of more accredited laboratories.