Quantitative expression analysis of Bodhesin genes in the buck (Capra hircus) reproductive tract by real-time polymerase chain reaction (qRT-PCR)

2009 ◽  
Vol 110 (3-4) ◽  
pp. 245-255 ◽  
Author(s):  
Luciana M. Melo ◽  
Antônia S.F. Nascimento ◽  
Felipe G. Silveira ◽  
Rodrigo M.S. Cunha ◽  
Nathália A.C. Tavares ◽  
...  
2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yang Zhang ◽  
Chunyang Dai ◽  
Huiyan Wang ◽  
Yong Gao ◽  
Tuantuan Li ◽  
...  

Abstract Background Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is posing a serious threat to global public health. Reverse transcriptase real-time quantitative polymerase chain reaction (qRT-PCR) is widely used as the gold standard for clinical detection of SARS-CoV-2. Due to technical limitations, the reported positive rates of qRT-PCR assay of throat swab samples vary from 30 to 60%. Therefore, the evaluation of alternative strategies to overcome the limitations of qRT-PCR is required. A previous study reported that one-step nested (OSN)-qRT-PCR revealed better suitability for detecting SARS-CoV-2. However, information on the analytical performance of OSN-qRT-PCR is insufficient. Method In this study, we aimed to analyze OSN-qRT-PCR by comparing it with droplet digital PCR (ddPCR) and qRT-PCR by using a dilution series of SARS-CoV-2 pseudoviral RNA and a quality assessment panel. The clinical performance of OSN-qRT-PCR was also validated and compared with ddPCR and qRT-PCR using specimens from COVID-19 patients. Result The limit of detection (copies/ml) of qRT-PCR, ddPCR, and OSN-qRT-PCR were 520.1 (95% CI: 363.23–1145.69) for ORF1ab and 528.1 (95% CI: 347.7–1248.7) for N, 401.8 (95% CI: 284.8–938.3) for ORF1ab and 336.8 (95% CI: 244.6–792.5) for N, and 194.74 (95% CI: 139.7–430.9) for ORF1ab and 189.1 (95% CI: 130.9–433.9) for N, respectively. Of the 34 clinical samples from COVID-19 patients, the positive rates of OSN-qRT-PCR, ddPCR, and qRT-PCR were 82.35% (28/34), 67.65% (23/34), and 58.82% (20/34), respectively. Conclusion In conclusion, the highly sensitive and specific OSN-qRT-PCR assay is superior to ddPCR and qRT-PCR assays, showing great potential as a technique for detection of SARS-CoV-2 in patients with low viral loads.


2005 ◽  
Vol 88 (2) ◽  
pp. 558-573 ◽  
Author(s):  
Max Feinberg ◽  
Sophie Fernandez ◽  
Sylvanie Cassard ◽  
Chrystèle Charles-Delobel ◽  
Yves Bertheau ◽  
...  

Abstract The European Committee for Standardization (CEN) and the European Network of GMO Working Laboratories have proposed development of a modular strategy for stepwise validation of complex analytical techniques. When applied to the quantitation of genetically modified organisms (GMOs) in food products, the instrumental quantitation step of the technique is separately validated from the DNA extraction step to better control the sources of uncertainty and facilitate the validation of GMO-specific polymerase chain reaction (PCR) tests. This paper presents the results of an interlaboratory study on the quantitation step of the method standardized by CEN for the detection of a regulatory element commonly inserted in GMO maize-based foods. This is focused on the quantitation of P35S promoter through using the quantitative real-time PCR (QRT-PCR). Fifteen French laboratories participated in the interlaboratory study of the P35S quantitation operating procedure on DNA extract samples using either the thermal cycler ABI Prism® 7700 (Applied Biosystems, Foster City, CA) or Light Cycler® (Roche Diagnostics, Indianapolis, IN). Attention was focused on DNA extract samples used to calibrate the method and unknown extract samples. Data were processed according to the recommendations of ISO 5725 standard. Performance criteria, obtained using the robust algorithm, were compared to the classic data processing after rejection of outliers by the Cochran and Grubbs tests. Two laboratories were detected as outliers by the Grubbs test. The robust precision criteria gave values between the classical values estimated before and after rejection of the outliers. Using the robust method, the relative expanded uncertainty by the quantitation method is about 20% for a 1% Bt176 content, whereas it can reach 40% for a 0.1% Bt176. The performances of the quantitation assay are relevant to the application of the European regulation, which has an accepted tolerance interval of about ±50%. These data were fitted to a power model (r2 = 0.96). Thanks to this model, it is possible to propose an estimation of uncertainty of the QRT-PCR quantitation step and an uncertainty budget depending on the analytical conditions.


2006 ◽  
Vol 16 (4) ◽  
pp. 395-403 ◽  
Author(s):  
Irina A. Afonina ◽  
Alan Mills ◽  
Silvia Sanders ◽  
Alena Kulchenko ◽  
Robert Dempcy ◽  
...  

2004 ◽  
Vol 16 (8) ◽  
pp. 753 ◽  
Author(s):  
Nermin El-Halawany ◽  
Siriluck Ponsuksili ◽  
Klaus Wimmers ◽  
Markus Gilles ◽  
Dawit Tesfaye ◽  
...  

The main objective of the present study was to analyse the quantitative expression pattern of genes from a subtracted blastocyst transcriptome throughout the preimplantation developmental stages of in vitro-produced bovine oocytes and embryos. For this purpose, Day 5 morula (M) cDNAs were subtracted from Day 7 blastocyst (B) cDNAs (B–M) and used to establish a B–M subtracted cDNA library, as reported previously. From the total generated clones, 19 were analysed quantitatively. The mRNA samples isolated from pools of immature oocytes (n = 150), mature oocytes (n = 150) and two-cell (n = 80), four-cell (n = 40), eight-cell (n = 20), morula (n = 6) and blastocyst (n = 3) embryos were reverse transcribed and subjected to real-time polymerase chain reaction (PCR) using sequence-specific primers and SYBR green as the DNA dye. A relative standard curve method was used to analyse the real-time data taking the morula stage as a calibrator. Applying suppression subtractive hybridisation (SSH), a total of 71 clones, which represent 33 different expressed sequence tags, were generated and available for analysis. Most transcripts were analysed for the first time in bovine embryogenesis. The real-time PCR has validated the results of SSH positively for 84% (16/19) of transcripts, whereas 16% (3/19) showed deviation in the expression pattern from the one seen during SSH. Several transcript-specific expression patterns were observed for genes that play decisive roles in bovine embryogenesis. In addition to identification, accurately quantifying the expression profiles of transcripts during development will pave the way towards understanding the molecular mechanisms of embryogenesis and their potential role in early embryo development. Most importantly, the present study has contributed to the enrichment of bovine embryo gene collection by generating new transcripts involved in bovine embryo development.


2020 ◽  
Author(s):  
Samantha Sperduti ◽  
Claudia Anzivino ◽  
Maria Teresa Villani ◽  
Gaetano De Feo ◽  
Manuela Simoni ◽  
...  

AbstractBackgroundQuantitative real time polymerase chain reaction (qPCR) and droplet digital PCR (ddPCR) are methods used for gene expression analysis in several contexts, including reproductive endocrinology.ObjectivesHerein, we compared qPCR and ddPCR technologies for gene expression analysis of hormone membrane receptor-encoding genes, such as follicle-stimulating hormone (FSHR), G protein-coupled estrogen (GPER) and choriogonadotropin receptors (LHCGR), as well as the commonly used RPS7 housekeeping gene, in order to identify the most reliable method to be applied for gene expression analysis in the context of human reproduction.MethodsTotal RNA was extracted from human primary granulosa cells of donor patients undergoing assisted reproduction and used for gene expression analysis by qPCR and ddPCR, after finding the optimal annealing temperature.ResultsBoth techniques provided results reflecting the low number of FSHR and GPER transcripts, although ddPCR detected also unspecific transcripts in using RPS7 primers and quantified the low-expressed genes with major accuracy, thanks to its higher reaction efficiency. The absolute FSHR and GPER transcript number was also determined by ddPCR, resulting in 50- to 170-fold lower amount than LHCGR transcripts.ConclusionThese results suggest that ddPCR is the candidate technology for analysis of genes with relatively low expression levels and provides useful insights for characterizing hormone receptor expression levels in the context of reproductive endocrinology.


2020 ◽  
Author(s):  
Yang Zhang ◽  
Chunyang Dai ◽  
Huiyan Wang ◽  
Yong Gao ◽  
Tuantuan Li ◽  
...  

Abstract Background Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is posing a serious threat to global public health. Reverse transcriptase real-time quantitative polymerase chain reaction (qRT-PCR) is widely used as the gold standard for clinical detection of SARS-CoV-2. Due to technical limitations, the reported positive rates of qRT-PCR assay of throat swab samples vary from 30–60%. Therefore, the evaluation of alternative strategies to overcome the limitations of qRT-PCR is required. A previous study reported that one-step nested (OSN)-qRT-PCR revealed better suitability for detecting SARS-CoV-2. However, information on the analytical performance of OSN-qRT-PCR is insufficient. Method: In this study, we aimed to analyze OSN-qRT-PCR by comparing it with droplet digital PCR (ddPCR) and qRT-PCR by using a dilution series of SARS-CoV-2 pseudoviral RNA and a quality assessment panel. The clinical performance of OSN-qRT-PCR was also validated and compared with ddPCR and qRT-PCR using specimens from COVID-19 patients. Result The LoD (copies/ml) of qRT-PCR, ddPCR, and OSN-qRT-PCR were 520.1 (95% CI): 363.23–1145.69) for ORF1ab and 528.1 (95% CI: 347.7–1248.7) for N, 401.8 (95% CI: 284.8–938.3) for ORF1ab and 336.8 (95% CI: 244.6–792.5) for N, and 194.74 (95% CI: 139.7–430.9) for ORF1ab and 189.1 (95% CI: 130.9–433.9) for N, respectively. Of the 34 clinical samples from COVID-19 patients, the positive rates of OSN-qRT-PCR, ddPCR, and qRT-PCR were 82.35% (28/34), 67.65% (23/34), and 58.82% (20/34), respectively. Conclusion In conclusion, the highly sensitive and specific OSN-qRT-PCR assay is superior to ddPCR and qRT-PCR assays, showing great potential as a technique for detection of SARS-CoV-2 in patients with low viral loads.


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