scholarly journals Enhanced Polymerase Chain Reaction Methods for Detecting and Quantifying Phytophthora infestans in Plants

2000 ◽  
Vol 90 (10) ◽  
pp. 1112-1119 ◽  
Author(s):  
Howard S. Judelson ◽  
Paul W. Tooley
Keyword(s):  
Polymerase Chain Reaction ◽  
Phytophthora Infestans ◽  
Positive Control ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Diagnostic Assays ◽  
Specificity And Sensitivity ◽  
Polymerase Chain ◽  
Primer Sets ◽  
Diagnostic Applications

Sensitive and specific primer sets for polymerase chain reaction (PCR) for Phytophthora infestans, the oomycete that causes late blight of potato and tomato, were developed based on families of highly repeated DNA. The performance of these primers was compared to those developed previously for the internal transcribed spacer (ITS) of ribosomal DNA. The detection limit using the new primers is 10 fg of P. infestans DNA, or 0.02 nuclei. This is about 100 times more sensitive than ITS-directed primers. Nested polymerase chain reaction (PCR) allows the measurement of down to 0.1 fg of DNA using the new primers. To enhance the reliability of diagnostic assays, an internal positive control was developed using an amplification mimic. The mimic also served as a competitor for quantitative PCR, which was used to assess the growth of P. infestans in resistant and susceptible tomato. A key dimension of this study was that two laboratories independently checked the specificity and sensitivity of each primer set; differences were noted that should be considered when PCR is adopted for diagnostic applications in any system.

Prenatal Diagnosis of Achondroplasia Using the Nested Polymerase Chain Reaction with Modified Primer Sets

1996 ◽  
Vol 11 (6) ◽  
pp. 407-413 ◽  
Author(s):  
Hideaki Sawai ◽  
Shinji Komori ◽  
Hiroyuki Tanaka ◽  
Kazuko Sakata ◽  
Takefumi Bessho ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Prenatal Diagnosis ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain ◽  
Primer Sets

Using a Polymerase Chain Reaction as a Complementary Test to Improve the Detection of Dermatophyte Fungus in Nails

2014 ◽  
Vol 104 (3) ◽  
pp. 233-237 ◽  
Author(s):  
María José Iglesias Sánchez ◽  
Ana María Pérez Pico ◽  
Félix Marcos Tejedor ◽  
María Jesús Iglesias Sánchez ◽  
Raquel Mayordomo Acevedo
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Sequences ◽  
Classical Method ◽  
Clinical Manifestations ◽  
Culture Method ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Traditional Procedure ◽  
Polymerase Chain

Background Dermatomycoses are a group of pathologic abnormalities frequently seen in clinical practice, and their prevalence has increased in recent decades. Diagnostic confirmation of mycotic infection in nails is essential because there are several pathologic conditions with similar clinical manifestations. The classical method for confirming the presence of fungus in nail is microbiological culture and the identification of morphological structures by microscopy. Methods We devised a nested polymerase chain reaction (PCR) that amplifies specific DNA sequences of dermatophyte fungus that is notably faster than the 3 to 4 weeks that the traditional procedure takes. We compared this new technique and the conventional plate culture method in 225 nail samples. The results were subjected to statistical analysis. Results We found concordance in 78.2% of the samples analyzed by the two methods and increased sensitivity when simultaneously using the two methods to analyze clinical samples. Now we can confirm the presence of dermatophyte fungus in most of the positive samples in just 24 hours, and we have to wait for the result of culture only in negative PCR cases. Conclusions Although this PCR cannot, at present, substitute for the traditional culture method in the detection of dermatophyte infection of the nails, it can be used as a complementary technique because its main advantage lies in the significant reduction of time used for diagnosis, in addition to higher sensitivity.

Detection of hepatitis “C” virus in formalin-fixed liver tissue by nested polymerase chain reaction

1992 ◽  
Vol 37 (4) ◽  
pp. 310-314 ◽  
Author(s):  
Richard Sallie ◽  
Anne Rayner ◽  
Bernard Portmann ◽  
A. L. W. F. Eddleston ◽  
Roger Williams
Keyword(s):  
Polymerase Chain Reaction ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Liver Tissue ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain ◽  
Formalin Fixed

The fate of a genetically modifiedPseudomonasstrain and its transgene during the composting of poultry manure

2004 ◽  
Vol 50 (6) ◽  
pp. 415-421 ◽  
Author(s):  
J Guan ◽  
J L Spencer ◽  
M Sampath ◽  
J Devenish
Keyword(s):  
Polymerase Chain Reaction ◽  
Incubation Temperature ◽  
Genetically Modified ◽  
Chicken Manure ◽  
Detection Sensitivity ◽  
Plate Count ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Soil Microcosms ◽  
Polymerase Chain

The fate of the genetically modified (GM) Pseudomonas chlororaphis strain 3732 RN-L11 and its transgene (lacZ insert) during composting of chicken manure was studied using plate count and nested polymerase chain reaction (PCR) methods. The detection sensitivity of the nested PCR method was 165 copies of the modified gene per gram of moist compost or soil. Compost microcosms consisted of a 100-g mixture of chicken manure and peat, whereas soil microcosms were 100-g samples of sandy clay loam. Each microcosm was inoculated with 4 × 1010CFU of P. chlororaphis RN-L11. In controlled temperature studies, neither P. chlororaphis RN-L11 nor its transgene could be detected in compost microcosms after incubation temperature was elevated to 45 °C or above for one or more days. In contrast, in the compost microcosms incubated at 23 °C, the target organism was not detected by the plate count method after 6 days, but its transgene was detectable for at least 45 days. In compost bins, the target organism was not recovered from compost microcosms or soil microcosms at different levels in the bins for 29 days. However, the transgene was detected in 8 of the 9 soil microcosms and in only 1 of the 9 compost microcosms. The compost microcosm in which transgene was detected was at the lower level of the bin where temperatures remained below 45 °C. The findings indicated that composting of organic wastes could be used to reduce or degrade heat sensitive GM microorganisms and their transgenes.Key words: composting, genetically modified Pseudomonas strain, transgene, polymerase chain reaction.

scholarly journals Detection of Helicobacter pylori using nested polymerase chain reaction in gastric biopsy samples

2008 ◽  
Vol 23 (3) ◽  
pp. 243-245 ◽  
Author(s):  
Divya Mahajan ◽  
Anju Jain ◽  
Varsha Singh ◽  
A. K. Jain ◽  
G. R. K. Rao ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Gastric Biopsy ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain
Sign in / Sign up

Export Citation Format

Share Document