scholarly journals Comparative analysis of genetically modified maize by implementation of a half-seed extraction technique

2007 ◽  
Author(s):  
◽  
Fernando Pienaar

The development of transgenic plants resulted in the need to utilize the various molecular methods (e.g., ELISA, real - time PCR etc.) for the detection or analysis of the presence or absence of a specific trait in a particular plant (Bt in this study). The overall aim of this study was to optimize a half – seed extraction technique as part of a laboratory protocol for transgenic maize plants and to explore the possibility of using the following molecular techniques: horizontal isoelectric focusing, real - time PCR and ELISA, as methods for detection of the Bt trait for incorporation into the half – seed extraction protocol.

2017 ◽  
Vol 7 (1) ◽  
pp. 32 ◽  
Author(s):  
Dimitra Houhoula ◽  
Stamatios Koussissis ◽  
Vladimiros Lougovois ◽  
John Tsaknis ◽  
Dimitra Kassavita ◽  
...  

The aim of the present study was the implementation of molecular techniques in the detection and quantification of allergic substances of peanut in various kinds of food products, e.g., breakfast cereals, chocolates and biscuits that are frequently related to allergies. In some cases, the presence of peanuts can be due to contamination during production and are not declared on the label. A total of 152 samples were collected from supermarkets and were analysed by a Real Time PCR method. The results indicated that 125 samples (83,3%) were found positive in peanut traces but the most important finding is that from the 84 samples that had no allergen declaration for peanuts, 48 (57,1%) of them were found positive. In conclusion, Real Time PCR can be a very important tool for the rapid detection and quantification of food allergens.


2007 ◽  
Vol 73 (24) ◽  
pp. 8012-8017 ◽  
Author(s):  
S. Wiedemann ◽  
P. Gürtler ◽  
C. Albrecht

ABSTRACT Rumen-cannulated cows (n = 4) were fed successively silage made from either conventional or genetically modified (GM) maize. Results revealed no effects of GM maize on the dynamics of six ruminal bacterial strains (investigated by real-time PCR) compared to the conventional maize silage.


2015 ◽  
Vol 21 (1-2) ◽  
Author(s):  
N. Czotter ◽  
E. Manduláné Farkas ◽  
R. Lózsa ◽  
I. Ember ◽  
G. Szûcsné Varga ◽  
...  

Several grapevine pathogens are disseminated by propagating material as systemic, but latent infections. Their detection and identification have a basic importance in the production and handling of propagating stocks. Thus several sensitive and reliable diagnostic protocols mostly based on molecular techniques have been developed. Of these methods quantitative real-time PCR (q-PCR) has recently got an emerging importance. Here we collected primer data for the detection and identification of grapevine pathogens which are important in the production of propagating stocks by q-PCR. Additional novel techniques that use DNA amplification, hybridization and  sequencing are also briefly reviewed.


2018 ◽  
Vol 56 (4) ◽  
Author(s):  
Beatrice Barda ◽  
Rahel Wampfler ◽  
Somphou Sayasone ◽  
Khampheng Phongluxa ◽  
Syda Xayavong ◽  
...  

ABSTRACT Strongyloides stercoralis is present worldwide, but its prevalence is still uncertain, mainly due to the lack of sensitivity of diagnostic methods. Molecular techniques are under development, but a standardized protocol is still unavailable. We compared the sensitivity of real-time PCR, using two extraction protocols, with that of the Baermann technique. Samples were collected in the framework of the baseline screening of a randomized clinical trial evaluating moxidectin against S. stercoralis in Lao People's Democratic Republic. Two stool samples from each participant were processed by the Baermann method, and one subsample was processed by PCR. DNA was extracted using the QIAamp DNA stool minikit based on the standard protocol for the QIAamp DNA minikit (QIA) and using a modification of the QIA procedure (POL). Subsequently, all extracted samples were analyzed by real-time PCR. Overall, 95 samples were analyzed by the three diagnostic methods. Sixty-nine (72.6%) samples were positive according to the Baermann method, 25 (26.3%) by the QIA method, and 62 (65.3%) by the POL method. The sensitivities were 86% (95% confidence interval [CI], 76.7 to 92.9), 31.0% (95% CI, 21.3 to 42.6), and 78.0% (95% CI, 66.8 to 86.1) for the Baermann, QIA, and POL methods, respectively. The sensitivities calculated for each day of the Baermann method separately were 60% (48.4 to 70.8%) and 64% (52.2 to 74.2%) for days 1 and 2, respectively. In conclusion, the POL method revealed a good performance and was comparable to the Baermann test performed on two stool samples and superior to the Baermann method performed on one stool sample. Additional studies are needed to standardize a PCR protocol for S. stercoralis diagnosis.


2020 ◽  
Vol 66 (4) ◽  
pp. 428-434
Author(s):  
Samia A Omer ◽  
Ishag Adam ◽  
Ali Noureldien ◽  
Hadeel Elhaj ◽  
Laura Guerrero-Latorre ◽  
...  

Abstract Diagnosis of congenital malaria is complicated by the low density of the parasite circulating in the cord blood and/or the peripheral blood of the newborns. Molecular techniques are significantly more sensitive than blood smears in detecting low-level parasitemia. This study investigated the prevalence of congenital malaria by the use of the real-time polymerase chain reaction (real-time PCR) in 102 babies born to mothers with microscopically confirmed infected placenta from Blue Nile state, Sudan. At delivery time, placental, maternal peripheral and cord blood samples in addition to samples collected from the newborns’ peripheral blood were examined for malaria infection using Giemsa-stained thick smear and parasite DNA detection by real-time PCR. The overall prevalence of congenital malaria includes the total babies with cord blood parasitaemia and peripheral blood parasitaemia was 18.6 and 56.8% using microscopy and real-time PCR, respectively. Even though all the neonates were aparasitaemic by microscopy, 19 (18.6%) of the babies had congenital malaria detected by real-time PCR, 15 (25.9%) of the babies with congenital malaria were born to mothers with both placental and peripheral blood malaria infections detected using the two techniques. Congenital malaria was significantly associated with cord blood malaria infections, maternal age and maternal haemoglobin level (p < 0.001). This first study investigating congenital malaria in Blue Nile state, Sudan shows that malaria-infected placenta resulted in infant and cord blood infections.


2002 ◽  
Vol 92 (7) ◽  
pp. 721-728 ◽  
Author(s):  
N. W. Schaad ◽  
D. Opgenorth ◽  
P. Gaush

Molecular-based techniques, such as polymerase chain reaction (PCR), can reduce the time needed for diagnosis of plant diseases when compared with classical isolation and pathogenicity tests. However, molecular techniques still require 2 to 3 days to complete. To the best of our knowledge, we describe for the first time a real-time PCR technique using a portable Smart Cycler for one-hour on-site diagnosis of an asymptomatic plant disease. Pierce's disease (PD) of grape, caused by the fastidious bacterium Xylella fastidiosa, causes serious losses in grapes in California and the southeastern United States. The disease has been difficult to diagnose because typical leaf scorching symptoms do not appear until late (June and after) in the season and the organism is very difficult to isolate early in the season. Sap and samples of macerated chips of secondary xylem from trunks of vines were used in a direct real-time PCR without extraction of DNA. Using two different sets of primers and probe, we diagnosed PD in 7 of 27 vines (26%) from four of six vineyards sampled 10 to 12 days after bud break in Kern, Tulare, and Napa counties of California. The diagnosis was confirmed by isolation of Xylella fastidiosa from two of the original PCR positive samples and later from symptomatic leaf petioles of four out of four vines from one vineyard that were originally PCR positive.


2017 ◽  
Vol 92 (1) ◽  
pp. 12-16 ◽  
Author(s):  
E. Dacal ◽  
J.M. Saugar ◽  
T. Soler ◽  
J.M. Azcárate ◽  
M.S. Jiménez ◽  
...  

AbstractStrongyloidiasis is usually an asymptomatic disease in immunocompetent patients, caused by Strongyloides stercoralis. However, in immunocompromised patients it can produce a severe clinical profile. Therefore, a correct diagnosis is necessary in these cases and in those chronic asymptomatic patients. The low sensitivity of classical parasitological techniques requires the analysis of multiple serial stool samples. Molecular diagnostic techniques represent an improvement in the detection of the parasite. The objective of this study was to evaluate the minimum number of samples necessary to achieve maximum sensitivity by real-time polymerase chain reaction (PCR). A total of 116 stool samples from 39 patients were analysed by direct microscopic observation, agar culture, Harada–Mori and real-time PCR, in one, two, three and four or more consecutive samples. After two serial samples, 6 out of 39 patients were positive by parasitological and molecular techniques, while 16 of them were real-time PCR positive, and all the patients detected by parasitology were also detected by the molecular technique, reaching 100.00% sensitivity versus 83.00% when analysing a single sample. These data also reflect apparently low specificity (51.52%) and positive predictive value (PPV) (27.27 %) values, due to the high number of cases detected by real-time PCR and not by parasitological techniques. These cases were confirmed as true positives when analysing three, four or more samples from the same patient. In conclusion, the application of molecular techniques decreases the number of serial stool samples necessary to give a diagnosis with the maximum sensitivity.


2010 ◽  
Vol 3 (4) ◽  
pp. 304-312 ◽  
Author(s):  
Silvia Folloni ◽  
Gianni Bellocchi ◽  
Adelina Prospero ◽  
Maddalena Querci ◽  
William Moens ◽  
...  

2014 ◽  
Vol 67 (9) ◽  
pp. 811-816 ◽  
Author(s):  
Samuel Boadi ◽  
Spencer D Polley ◽  
Sally Kilburn ◽  
Graham A Mills ◽  
Peter L Chiodini

IntroductionGiardiasis is an intestinal diarrhoeal illness caused by the flagellate protozoan parasite Giardia intestinalis. Molecular techniques for the identification of G. intestinalis have generally been shown to offer a better detection rate of the parasite than the traditional faecal concentration and microscopy techniques.AimThe aim of this study was to critically assess the performance of a commercial and a published real-time PCR assay for their potential use as frontline tests for the diagnosis of giardiasis.MethodsA composite reference standard of enzyme immunoassay and rapid membrane test was used in a diagnostic accuracy study to assess the performance of Primerdesign's, and Verweij et alG. intestinalis real-time PCR assays, comparing them with the traditional ova, cysts and parasite microscopy test (OCP-M).ResultsThe Verweij real-time PCR used primers for the (SSU) rRNA gene, and produced a diagnostic sensitivity of 93.4% (95% CI 88.30% to 98.50%) and an efficiency of 100%. Primerdesign's real-time PCR used primers for the glutamate dehydrogenase gene and produced a diagnostic sensitivity of 61.5% (95% CI 51.50% to 71.50%) and an efficiency of 203%. The OCP-M sensitivity was 83.5% (95% CI 75.87% to 91.13%).ConclusionsThe Verweij real-time PCR was robust and the most sensitive assay suited for use as a first-line diagnostic test for giardiasis.


2005 ◽  
Vol 98 (4) ◽  
pp. 1526-1533 ◽  
Author(s):  
Michael Fayon ◽  
Eric Dumas De La Roque ◽  
Patrick Berger ◽  
Hugues Begueret ◽  
Olga Ousova ◽  
...  

Spontaneous or agonist-induced contraction of airway smooth muscle can be observed very early in fetal life, thus explaining the possible occurrence of bronchospasm in very low birth weight infants within the first days of life. In an attempt to better manage such bronchospasms, the aim of the present study was to investigate the age-specific modifications in airway smooth muscle relaxation to β2-agonists and muscarinic antagonists using a combination of functional and molecular techniques. In the rat, isometric relaxation to the β2-agonist salbutamol was examined in tracheae; we also examined muscarinic receptor expression (M2R and M3R mRNA levels) in airway smooth muscle by immunochemistry, Western blotting, and real-time PCR. Compared with adults, salbutamol-induced relaxation was twofold greater in immature rat isolated tracheae preconstricted by carbachol. This effect was associated with a lower expression of M2R in the smooth muscle of immature animals (sixfold and almost twofold as assessed by immunochemistry and Western blotting, respectively). Real-time PCR data indicate that changes in M2R expression according to age occurred at a posttranscriptional level. In adult airways, there was a significantly greater functional efficacy of M2R blockade by methoctramine compared with that shown in immature rats. Because of the limited availability of human neonate lung tissue, only the molecular part of the study was performed, and we observed a qualitatively similar effect, i.e., a lower M2R expression in the neonatal airway smooth muscle, although this was quantitatively smaller. We conclude that β2-agonist-induced relaxation is enhanced in immature compared with adult airways as a result of greater postjunctional M2R expression in adult airway smooth muscle. This finding may be of importance in the clinical management of bronchoconstriction in neonates.


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