The polymerase chain reaction (PCR) is a powerful and widely used technique that has greatly advanced our ability to analyze genes. Genomic deoxyribonucleic acid (DNA) present in cells contains many thousands of genes. This makes it difficult to isolate and analyze any individual gene. PCR allows specific DNA sequences, usually corresponding to genes or parts of genes, to be copied from genomic...

A PCR-coupled ligase chain reaction (LCR) assay was developed to distinguish the plant pathogenic bacterium Erwinia stewartii from other erwiniae. This new technique allows discrimination to the species level on the basis of a single-base-pair difference in the 16S rRNA gene which is unique to E. stewartii. Portions of the 16S rRNA genes ofE. stewartii and the closely related Erwinia herbicola ...

PCR depends on generation of a deoxyoligonucleotide complementary to the known 3' terminus of the portion of DNA to be amplified. This is then annealed with the appropriate strand of heat-denatured DNA and used as a primer for synthesis by a DNA polymerase of a full-length complementary strand (Fig. 1). The two strands are then separated by heat denaturation and the process repeated. However, i...

Introduction Polymerases are fascinating and ubiquitous enzymes that catalyse the synthesis of nucleic acids with impressive rates and fidelity. Indeed, polymerases are capable of distinguishing minute differences in nucleoside triphosphates (e.g. the 2'OH residue that is absent in dNTPs but present in rNTPs) and process with very low error rates (~106 for Pfu DNA polymerase, e.g.). However, th...

This essay on the polymerase chain reaction is one of a series developed as part of FASEB's efforts to educate the general public, and the legislators whom it elects, about the benefits of fundamental biomedical research-particularly how investment in such research leads to scientific progress, improved health, and economic well-being.

After vascular injury, a cascade of serine protease activations leads to the conversion of the soluble fibrinogen molecule into fibrin. The fibrin monomers then polymerize spontaneously and noncovalently to form a fibrin gel. The primary interaction of this polymerization reaction is between the newly exposed N-terminal Gly-Pro-Arg sequence of the a chain of one fibrin molecule and the C-termin...

Dear Editor-in-Chief We read with interest the study by Khazaei et al. (1) in which the authors have nicely concluded that PCR is more sensitive test than Ziehl-Neelsen staining and histo-pathological examination for the diagnosis of tuberculosis (TB). They have rightly pointed to use PCR, selectively, in acidfast bacilli negative paucibacillary forms of TB. However, we intend to highlight few...

background: erysipelothrix rhusiopathiae (e. rhusiopathiae) is generally transmitted into the gastrointestinal tract of animals by the intake of contaminated food or water and causes great economic loss in agriculture worldwide. some of the erysipelothrix spp. are the causative agents of erysipeloid, which is an occupational infection in humans. the aim of the present study was to isolate e. rh...

conclusions in conclusion, the prevalence of hcv genotype 1 was 51.7%, which was lower than the rates reported in other studies in turkey, while the prevalence of hcv genotype 3 was 46%, which was remarkably higher than the reported turkish data. in addition, the prevalence rate for genotype 3 reported in the present study is the highest that has ever been reported in the literature. results th...