RT qPCR Dotaz Zobrazit nápovědu
Reverse transcription quantitative PCR (RT-qPCR) has delivered significant insights in understanding the gene expression landscape. Thanks to its precision, sensitivity, flexibility, and cost effectiveness, RT-qPCR has also found utility in advanced single-cell analysis. Single-cell RT-qPCR now represents a well-established method, suitable for an efficient screening prior to single-cell RNA sequencing (scRNA-Seq) experiments, or, oppositely, for validation of hypotheses formulated from high-throughput approaches. Here, we aim to provide a comprehensive summary of the scRT-qPCR method by discussing the limitations of single-cell collection methods, describing the importance of reverse transcription, providing recommendations for the preamplification and primer design, and summarizing essential data processing steps. With the detailed protocol attached in the appendix, this tutorial provides a set of guidelines that allow any researcher to perform scRT-qPCR measurements of the highest standard.
- Klíčová slova
- RT-qPCR, gene expression, preamplification, quantitative PCR, reverse transcription, sample collection, single cell,
- MeSH
- analýza jednotlivých buněk metody normy MeSH
- kvantitativní polymerázová řetězová reakce metody normy MeSH
- lidé MeSH
- reverzní transkripce genetika MeSH
- senzitivita a specificita MeSH
- stanovení celkové genové exprese metody normy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Reverse-transcription quantitative PCR (RT-qPCR) is currently the most sensitive method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19). We analysed 1927 samples collected in a local public hospital during the autumn 2020 peak of the pandemic in the Czech Republic. The tests were performed using the Seegene Allplex 2019-nCov assay, which simultaneously detects three SARS-CoV-2 genes. In all samples analysed, 44.5 % were negative for all three genes, and 37.6 % were undoubtedly positive, with all three viral genes being amplified. A high degree of correlation between C t values among the genes confirmed the internal consistency of testing. Most of the positive samples were detected between the 15th and 35th cycles. We also registered a small number of samples with only one (13.2 %) or two (4.7 %) amplified genes, which may have originated from either freshly infected or already recovering patients. In addition, we did not detect any potentially false-positive samples from low-prevalence settings. Our results document that PCR testing represents a reliable and robust method for routine diagnostic detection of SARS-CoV-2.
- Klíčová slova
- COVID-19, RT-qPCR testing, SARS-CoV-2, cycle threshold,
- Publikační typ
- časopisecké články MeSH
We performed a gene expression study using RT-qPCR in Staphylococcus aureus. The influence of normalization method was investigated. We confirmed that a recent standard, using more reference genes, was the best normalization strategy. The application of the most commonly used reference genes in 2011 (gyrB and 16S rRNA gene) failed.
- MeSH
- bakteriální geny * MeSH
- bakteriální RNA genetika MeSH
- DNA gyráza genetika MeSH
- exprese genu MeSH
- kvantitativní polymerázová řetězová reakce normy MeSH
- polymerázová řetězová reakce s reverzní transkripcí normy MeSH
- referenční standardy MeSH
- RNA ribozomální 16S genetika MeSH
- Staphylococcus aureus genetika MeSH
- transkriptom MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bakteriální RNA MeSH
- DNA gyráza MeSH
- RNA ribozomální 16S MeSH
The mutual dependence of human and animal health is central to the One Health initiative as an integrated strategy for infectious disease control and management. A crucial element of the One Health includes preparation and response to influenza A virus (IAV) threats at the human-animal interface. The IAVs are characterized by extensive genetic variability, they circulate among different hosts and can establish host-specific lineages. The four main hosts are: avian, swine, human and equine, with occasional transmission to other mammalian species. The host diversity is mirrored in the range of the RT-qPCR assays for IAV detection. Different assays are recommended by the responsible health authorities for generic IAV detection in birds, swine or humans. In order to unify IAV monitoring in different hosts and apply the One Health approach, we developed a single RT-qPCR assay for universal detection of all IAVs of all subtypes, species origin and global distribution. The assay design was centred on a highly conserved region of the IAV matrix protein (MP)-segment identified by a comprehensive analysis of 99,353 sequences. The reaction parameters were effectively optimised with efficiency of 93-97% and LOD95% of approximately ten IAV templates per reaction. The assay showed high repeatability, reproducibility and robustness. The extensive in silico evaluation demonstrated high inclusivity, i.e. perfect sequence match in the primers and probe binding regions, established as 94.6% for swine, 98.2% for avian and 100% for human H3N2, pandemic H1N1, as well as other IAV strains, resulting in an overall predicted detection rate of 99% on the analysed dataset. The theoretical predictions were confirmed and extensively validated by collaboration between six veterinary or human diagnostic laboratories on a total of 1970 specimens, of which 1455 were clinical and included a diverse panel of IAV strains.
- MeSH
- chřipka lidská diagnóza virologie MeSH
- infekce viry z čeledi Orthomyxoviridae diagnóza virologie MeSH
- lidé MeSH
- nemoci prasat diagnóza virologie MeSH
- One Health MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody MeSH
- prasata MeSH
- ptačí chřipka u ptáků diagnóza virologie MeSH
- ptáci virologie MeSH
- reprodukovatelnost výsledků MeSH
- virus chřipky A, podtyp H1N1 genetika izolace a purifikace MeSH
- virus chřipky A, podtyp H3N2 genetika izolace a purifikace MeSH
- virus chřipky A genetika izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
MicroRNAs are a class of small non-coding RNAs that serve as important regulators of gene expression at the posttranscriptional level. They are stable in body fluids and pose great potential to serve as biomarkers. Here, we present a highly specific, sensitive and cost-effective system to quantify miRNA expression based on two-step RT-qPCR with SYBR-green detection chemistry called Two-tailed RT-qPCR. It takes advantage of novel, target-specific primers for reverse transcription composed of two hemiprobes complementary to two different parts of the targeted miRNA, connected by a hairpin structure. The introduction of a second probe ensures high sensitivity and enables discrimination of highly homologous miRNAs irrespectively of the position of the mismatched nucleotide. Two-tailed RT-qPCR has a dynamic range of seven logs and a sensitivity sufficient to detect down to ten target miRNA molecules. It is capable to capture the full isomiR repertoire, leading to accurate representation of the complete miRNA content in a sample. The reverse transcription step can be multiplexed and the miRNA profiles measured with Two-tailed RT-qPCR show excellent correlation with the industry standard TaqMan miRNA assays (r2 = 0.985). Moreover, Two-tailed RT-qPCR allows for rapid testing with a total analysis time of less than 2.5 hours.
- MeSH
- kvantitativní polymerázová řetězová reakce metody MeSH
- mikro RNA analýza genetika MeSH
- myši MeSH
- prekurzory RNA analýza genetika MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- stanovení celkové genové exprese metody MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- validační studie MeSH
- Názvy látek
- mikro RNA MeSH
- prekurzory RNA MeSH
The ongoing evolution of microbial pathogens represents a significant issue in diagnostic PCR/qPCR. Many assays are burdened with false negativity due to mispriming and/or probe-binding failures. Therefore, PCR/qPCR assays used in the laboratory should be periodically re-assessed in silico on public sequences to evaluate the ability to detect actually circulating strains and to infer potentially escaping variants. In the work presented we re-assessed a RT-qPCR assay for the universal detection of influenza A (IA) viruses currently recommended by the European Union Reference Laboratory for Avian Influenza. To this end, the primers and probe sequences were challenged against more than 99,000 M-segment sequences in five data pools. To streamline this process, we developed a simple algorithm called the SequenceTracer designed for alignment stratification, compression, and personal sequence subset selection and also demonstrated its utility. The re-assessment confirmed the high inclusivity of the assay for the detection of avian, swine and human pandemic H1N1 IA viruses. On the other hand, the analysis identified human H3N2 strains with a critical probe-interfering mutation circulating since 2010, albeit with a significantly fluctuating proportion. Minor variations located in the forward and reverse primers identified in the avian and swine data were also considered.
The merit of RNASeq data relies heavily on correct normalization. However, most methods assume that the majority of transcripts show no differential expression between conditions. This assumption may not always be correct, especially when one condition results in overexpression. We present a new method (NormQ) to normalize the RNASeq library size, using the relative proportion observed from RT-qPCR of selected marker genes. The method was compared against the popular median-of-ratios method, using simulated and real-datasets. NormQ produced more matches to differentially expressed genes in the simulated dataset and more distribution profile matches for both simulated and real datasets.
- Klíčová slova
- DESeq, Median-of-ratios, Normalization, RNASeq, TOMOSeq, Transcriptomics,
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: The aim of this study was to compare results of two commercially available kits used for routine detection of Rotavirus A in human stool samples with results of commercial quantitative reverse-transcription PCR (RT-qPCR) test and in-house RT-qPCR. MATERIAL AND METHODS: In total, 749 stool samples were screen-ed with the use of four different methods. The samples were collected from four diagnostic laboratories from March 2016 to June 2017. Diagnose of gastrointestinal disorders was stated in one third of tested patients, the rest of samples was collected from patients with other primary diagnose. The samples were tested with the enzymatic immunoassay (EIA) (RIDASCREEN® Rotavirus) and with rapid diagnostic immunochromatographic test (RDT) (IMMUNOQUICK® No-Rot-Adeno). As a reference method a commercial RT-qPCR test was used (Primerdesign Genesig® Kit) and it was compared with in-house RT-qPCR test prepared in our laboratory. The samples which in the reference RT-qPCR gave positive signal of reaction in cycle 28 or higher (Ct 28) were assessed as negatives in order to include only samples with some clinical relevance into sensitivity determination. RESULTS: Diagnostic sensitivity was assessed as 84.2% for EIA and 82.5% for RDT. The specificity of those tests was calculated as 97.8% for EIA and 96.4% for RDT. The performance of both diagnostic tests describing their positive predictive value was determined to be 87.3% for EIA and 80.3% for RDT. Negative predictive value was calculated to be 97.2% for EIA and 96.8% for RDT. Proportion of RVA-positive samples determined with the reference RT-qPCR test with our own cut-off level was 15.2% (n=114). Comparisons of the in-house and reference RT-qPCR tests showed very good agreement of results. The sensitivity of the in-house test was 100% and its specificity 99.7%. CONCLUSIONS: RT-qPCR is more sensitive for surveillance of rotavirus gastroenteritis than routinely used EIA or RDT methods. The specificity of both evaluated tests was very high. However, EIA was in all performance parameters assessed better than RDT.
- Klíčová slova
- rotavirus A - enzymatic immunoassay - immunochromato-graphic test - RT-qPCR, rotavirus A - enzymatic immunoassay - immunochromato-graphic test - RT-qPCR.,
- MeSH
- chromatografie * normy MeSH
- feces virologie MeSH
- gastrointestinální nemoci diagnóza virologie MeSH
- imunoanalýza normy MeSH
- imunoenzymatické techniky * normy MeSH
- lidé MeSH
- polymerázová řetězová reakce s reverzní transkripcí * normy MeSH
- rotavirové infekce * MeSH
- Rotavirus * izolace a purifikace MeSH
- senzitivita a specificita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Circulating cell-free microRNAs are promising candidates for minimally invasive clinical biomarkers for the diagnosis, prognosis and monitoring of many human diseases. Despite substantial efforts invested in the field, the research so far has failed to deliver expected results. One of the contributing factors is general lack of agreement between various studies, partly due to the considerable technical challenges accompanying the workflow. Pre-analytical variables including sample collection, RNA isolation, and quantification are sources of bias that may hamper biological interpretation of the results. Here, we present a Two-tailed RT-qPCR panel for quality control, monitoring of technical performance, and optimization of microRNA profiling experiments from biofluid samples. The Two-tailed QC (quality control) panel is based on two sets of synthetic spike-in molecules and three endogenous microRNAs that are quantified with the highly specific Two-tailed RT-qPCR technology. The QC panel is a cost-effective way to assess quality of isolated microRNA, degree of inhibition, and erythrocyte contamination to ensure technical soundness of the obtained results. We provide assay sequences, detailed experimental protocol and guide to data interpretation. The application of the QC panel is demonstrated on the optimization of RNA isolation from biofluids with the miRNeasy Serum/Plasma Advanced Kit (Qiagen).
- MeSH
- analýza nákladů a výnosů MeSH
- biologické markery krev MeSH
- cirkulující mikroRNA krev izolace a purifikace MeSH
- krysa rodu Rattus MeSH
- kvantitativní polymerázová řetězová reakce ekonomika přístrojové vybavení metody normy MeSH
- lidé MeSH
- reagenční diagnostické soupravy normy MeSH
- řízení kvality * MeSH
- studie proveditelnosti MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
- cirkulující mikroRNA MeSH
- reagenční diagnostické soupravy MeSH
Accuracy and transparency of scientific data are becoming more and more relevant with the increasing concern regarding the evaluation of data reproducibility in many research areas. This concern is also true for quantifying coding and noncoding RNAs, with the remarkable increase in publications reporting RNA profiling and sequencing studies. To address the problem, we propose the following recommendations: (a) accurate documentation of experimental procedures in Materials and methods (and not only in the supplementary information, as many journals have a strict mandate for making Materials and methods as visible as possible in the main text); (b) submission of RT-qPCR raw data for all experiments reported; and (c) adoption of a unified, simple format for submitted RT-qPCR raw data. The Real-time PCR Data Essential Spreadsheet Format (RDES) was created for this purpose.
- Klíčová slova
- RNA, RT-qPCR, accuracy, quantification,
- MeSH
- kvantitativní polymerázová řetězová reakce metody MeSH
- lidé MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- reprodukovatelnost výsledků MeSH
- RNA * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- RNA * MeSH
