Quantitative Real-Time RT-PCR (qRT-PCR) of Zebrafish Transcripts: Optimization of RNA Extraction, Quality Control Considerations, and Data Analysis

2009 ◽  
Vol 2009 (10) ◽  
pp. pdb.prot5314-pdb.prot5314 ◽  
Author(s):  
C.-C. Lan ◽  
R. Tang ◽  
I. Un San Leong ◽  
D. R. Love
Keyword(s):  
Quality Control ◽  
Data Analysis ◽  
Real Time ◽  
Rna Extraction ◽  
Rt Pcr ◽  
Qrt Pcr

scholarly journals Development of an RNA Extraction Protocol for a Norovirus from Raw Oysters and Detection by qRT-PCR and Droplet-Digital RT-PCR

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1804
Author(s):  
Daniel Plante ◽  
Julio Alexander Bran Barrera ◽  
Maude Lord ◽  
Irène Iugovaz ◽  
Neda Nasheri
Keyword(s):  
Hepatitis A Virus ◽  
Rna Extraction ◽  
Complex Nature ◽  
Murine Norovirus ◽  
Rt Pcr ◽  
Pcr Inhibitors ◽  
Qrt Pcr ◽  
Extraction Protocol ◽  
Viral Particles ◽  
Hands On

Foodborne viruses such as norovirus and hepatitis A virus cause frequent outbreaks associated with the consumption of raw or undercooked oysters. Viral particles are bioaccumulated in the oyster’s digestive glands, making RNA extraction and RT-PCR detection difficult due to the complex nature of the food matrix and the presence of RT-PCR inhibitors. Herein, we have developed a viral RNA extraction protocol from raw oysters using murine norovirus (MNV) as a surrogate for human noroviruses. The method combines lysis in Tri-Reagent reagent, followed by RNA extraction using Direct-Zol purification columns and lithium chloride precipitation. Viral load quantification was performed by both qRT-PCR and droplet-digital RT-PCR. We have demonstrated that this method can efficiently remove RT-PCR inhibitors, and is sensitive enough to reliably detect viral contamination at 25 PFU/0.2 g. We have also compared the efficiency of this method with the ISO 15216-1:2017 method and Method E developed by Quang and colleagues, and observed significantly higher efficiency compared with the ISO 15216-1 method and comparable efficiency with Method E, with less steps, and shorter hands-on time.

Quantitative real-time RT-PCR data analysis: current concepts and the novel “gene expression’s C T difference” formula

2006 ◽  
Vol 84 (11) ◽  
pp. 901-910 ◽  
Author(s):  
Jan H. Schefe ◽  
Kerstin E. Lehmann ◽  
Ivo R. Buschmann ◽  
Thomas Unger ◽  
Heiko Funke-Kaiser
Keyword(s):  
Data Analysis ◽  
Real Time ◽  
The Novel ◽  
Rt Pcr ◽  
Novel Gene ◽  
Difference Formula

scholarly journals Evaluation of the performance of the COVID-19 rapid antigen tests in a tertiary level hospital in Bangladesh.

2021 ◽  
Author(s):  
Mohammad Jahidur Rahman Khan ◽  
Md. Shahadat Hossain ◽  
Samshad Jahan Shumu ◽  
Md. Selim Reza ◽  
Farzana Mim ◽  
...  
Keyword(s):  
Viral Load ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Detection Rate ◽  
High Sensitivity ◽  
Rt Pcr ◽  
College Hospital ◽  
Medical College ◽  
Qrt Pcr ◽  
Antigen Tests

Abstract Background: While the COVID-19 pandemic is a worldwide crisis, tests with high sensitivity and specificity are essential for identifying and managing COVID-19 patients. Globally, several rapid antigen tests RATs for COVID-19 have been developed, but their clinical efficacy has not been well established. This study aimed to evaluate the performance of several rapid antigen tests (RATs) to diagnose SARS-CoV-2 infection.Methods: This prospective observational study was conducted at Shaheed Suhrawardy Medical College hospital from February 2021 to April 2021 in Dhaka, Bangladesh. This study included the patients admitted in this hospital at the COVID-19 isolation unit or referred from the triage facility of the outdoor department of this hospital suspected as COVID-19 case. Two nasopharyngeal samples were collected simultaneously. one sample was used on the spot for the RAT. The other was sent to the adjacent Shaheed Suhrawardy Medical College COVID-19 RT-PCR laboratory for real-time reverse transcription-polymerase chain reaction (qRT-PCR). The performance of the RAT was evaluated using the results of qRT-PCR as a reference.Results: A total of 223 patients were included in this study, and the real-time RT-PCR detected SARS-CoV-2 in 84 (37.7%) patients. Of these 84 patients, 9 (10.7%) were asymptomatic. The overall sensitivity and specificity of RATs were 78.6% and 99.3%, respectively. The sensitivity was 81.3% in symptomatic cases and 55.6% in asymptomatic cases. False-negatives were observed in 18 patients, 3 of whom were asymptomatic and had a low viral load (cycle threshold (Ct) > 30). The detection rate of RATs was 100% when the Ct value was up to 24. The detection rate was 42.3% when the Ct was >29. The detection rate of RATs was 92.3% when the onset of symptoms was within three days. The detection rate was 33.3% when the onset of symptoms was >7 days.Conclusions: RATs for COVID-19 used in this study delivered an acceptable performance in patients with high viral load and within the first week of the onset of symptoms. They can be used as a supplementary method to RT-PCR for the diagnosis of COVID-19 patients.

scholarly journals Comparison of Six RNA Extraction Methods for the Detection of Classical Swine Fever Virus by Real-Time and Conventional Reverse Transcription–PCR

2005 ◽  
Vol 17 (6) ◽  
pp. 574-578 ◽  
Author(s):  
Ming Y. Deng ◽  
He Wang ◽  
Gordon B. Ward ◽  
Tammy R. Beckham ◽  
Thomas S. McKenna
Keyword(s):  
Real Time ◽  
Classical Swine Fever Virus ◽  
Rna Extraction ◽  
Classical Swine Fever ◽  
Extraction Methods ◽  
Rt Pcr ◽  
Total Rna ◽  
Reverse Transcription Pcr ◽  
Rna Extraction Methods ◽  
Positive Results

Six RNA extraction methods, i.e., RNAqueous kit, Micro-to-midi total RNA purification system, NucleoSpin RNA II, GenElute mammalian total RNA kit, RNeasy mini kit, and TRIzol LS reagent, were evaluated on blood and 7 tissues from pig infected with classical swine fever virus (CSFV). Each of the 6 extraction methods yielded sufficient RNA for positive results in a real-time reverse transcription–PCR (RT-PCR) for CSFV, and all RNA, except the one extracted from blood by TRIzol LS reagent, yielded positive results in both a conventional RT-PCR for CSFV and a conventional RT-PCR for an endogenous gene encoding β-actin. The RNA extracted from blood by TRIzol LS reagent became positive in both conventional RT-PCR assays when it was diluted to 1:2, 1:4, or up to 1:64 in nuclease-free water. It is concluded that all 6 methods are more or less useful for the detection of CSFV by real-time and conventional RT-PCR in swine blood and tissues. However, some of the 6 reagents offer certain advantages not common to all 6 extraction procedures. For example, RNA extracted by the TRIzol LS reagent constantly had the highest yield; that by the RNAqueous kit had the highest A260/A280 ratio for almost all samples; and that by the NucleoSpin RNA II and the GenElute mammalian total RNA kit was most likely to be free of contaminations with genomic DNA.

Paper or Plastic: RT-PCR of BCR-ABL from Blood Spots Stored and Shipped on Paper

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4566-4566
Author(s):  
Olga Sala Torra ◽  
Lan Beppu ◽  
Susan Branford ◽  
Linda Fletcher ◽  
Gooley Ted ◽  
...  
Keyword(s):  
Room Temperature ◽  
Time Course ◽  
Rna Extraction ◽  
Dried Blood Spots ◽  
Rt Pcr ◽  
Fresh Blood ◽  
Blood Samples ◽  
Blood Spots ◽  
Qrt Pcr ◽  
Sample Age

Abstract In many parts of the world, diagnosis and monitoring of CML patients is limited by the availability and cost of molecular testing. In countries without molecular diagnostic capabilities, blood samples can be shipped to central labs, but this is both hampered by sample degradation, and the high costs of shipping. This study explores the method of directly spotting peripheral blood onto a paper template (dried blood spots), with subsequent shipping, RNA extraction, and BCR-ABL testing. Methods: Blood Spots and Shipment. We received dried blood spots from Australia and African countries by mail or courier, and blood from CML patients from our institution were also used for these experiments. 200μL of blood (PB) was pipetted onto Whatman 503 Protein Saver Cards (PSC; Sigma-Aldrich), where each card contains four 50μL spots. Cards were allowed to dry for at least 24 hours at room temperature. For mailing, PSCs were sealed into glassine envelopes with a packet of desiccant, and then placed inside a mailing envelope following DOT and IATA regulation for shipping non-regulated, exempt human specimens. RNA Extraction from Cards and %BCR-ABL determination. Blood spots were incubated with proteinase K followed by RNA isolation using RNeasy Mini Kits (Qiagen). Extracted RNA was quantified using a NanoDrop spectrometer (Thermo Scientific). %BCR-ABL was determined using the automated Cepheid GeneXpert platform or manual two-step quantitative RT-PCR on the 7900HT Fast Real-Time PCR System (Applied Biosystems). Results: Bench top time course: To test for effects of long transit times on RNA quality, we performed a time course study of cards at room temperature (RT) with 5 samples. For each sample, multiple cards were spotted with PB. The cards were then allowed to sit at RT for predetermined amounts of time, up to 42 days, before extracting RNA. We measured RNA integrity for one of the specimens (CML # 5) and found rapid degradation with the RIN number going from 8.7 for the fresh blood to 2.8 after 28 days on the card. However the amplification for both BCR-ABL and ABL differed less than one cycle between the fresh blood and the last time point by manual qRT-PCR (BCR-ABL Ct = 23.63 for fresh blood and 24.06 for day 28 PSC; ABL Ct = 26.69 for fresh blood and 27.64 for day 28 PSC). Figure 1 shows the results of the time course experiment for the 5 samples as a plot of ΔCt versus time in days. BCR-ABL qRT-PCR concordance studies: We compared the %BCR-ABL results obtained in fresh specimen at the institution sending the sample with the %BCR-ABL results we obtained from RNA extracted from PSC using the Cepheid GeneXpert. Paired evaluable results were available for 9 samples with a median WBC = 9.8 x 109/L (range: 3.37x109/L – 85.5x109/L). Samples were 8 to 49 days old at the time of extraction. The amount of RNA input into the GeneXpert reaction ranged from 38.75ng to 1μg. The %BCR-ABL detected ranged from 0.37% to 27% (see Table). The mean absolute difference between fresh blood and PSC BCR-ABL% is 2%; the relative mean percent change for BCR-ABL, using fresh blood as the reference is 13.1% (S.D., 31.2), P = 0.24. Conclusions and future directions: Dried blood spots are relatively inexpensive method to transport blood that preserves enough RNA stability to allow highly accurate BCR-ABL detection, when compared to results performed on an identical platform using fresh peripheral blood samples. Further studies are undergoing to accurately determine the sensitivity of this method and the feasibility of using regular mail for inexpensive transport of specimens. Table 1IDWBC (1000/μL)Sample Age at Spotting (Days)Sample Age at RNA extraction (Days)RNA ng/μlVolume GeneXPert (μL)Paper %BCR-ABL (IS)GeneXpertFresh Blood % BCR-ABL (IS) GeneXpertI1na010426349naI224.101311092745I38009181544naI47.4285102.4*3.1I55.50495241.92I63.61307.4225912I785.5130102102439I812.212912.415128.8I9na1281.5250.37*0.71I103.370273257.85.7I1115.912731102325I126.612714.415na2.3 *%BCR-ABL was manually calculated due to late ABL Cts because of low starting material. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

SPOT REAL-TIME RT-PCR: A METHOD FOR DIRECT DETECTION OF PLUM POX VIRUS AVOIDING RNA EXTRACTION

2008 ◽  
pp. 215-220
Author(s):  
N. Capote ◽  
E. Bertolini ◽  
M.C. Martínez ◽  
A. Olmos ◽  
M.T. Gorris ◽  
...  
Keyword(s):  
Real Time ◽  
Direct Detection ◽  
Rna Extraction ◽  
Plum Pox Virus ◽  
Rt Pcr

scholarly journals Assessment of Successful qRT-PCR of SARS-CoV-2 Assay in Pool Screening Using Isopropyl Alcohol Purification Step in RNA Extraction

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Mayank Gangwar ◽  
Alka Shukla ◽  
Virendra Kumar Patel ◽  
Pradyot Prakash ◽  
Gopal Nath
Keyword(s):  
Isopropyl Alcohol ◽  
Rna Extraction ◽  
Group Testing ◽  
Research Work ◽  
Rt Pcr ◽  
Purification Step ◽  
E Gene ◽  
Qrt Pcr ◽  
Pcr Targeting ◽  
Pooled Samples

The study is aimed at establishing the optimal parameters for RNA purification of pooled specimens, in SARS-CoV-2 assay. This research work evaluates the difference of extracted RNA purity of pooled samples with and without treatment with isopropyl alcohol and its effect on real-time RT-PCR. As per the protocol of the Indian Council of Medical Research (ICMR), 5 sample pools were analysed using qRT-PCR. A total of 100 pooled samples were selected for the study by mixing 50 μL of one COVID-19 positive nasopharyngeal/oropharyngeal (NP/OP) specimen and 50 μL each of 4 known negative specimens. Pool RNA was extracted using the column-based method, and 1 set of pooled extracted RNA was tested as such, while RNA of the second set was treated additionally with chilled isopropyl alcohol (modified protocol). Further, the purity of extracted RNA in both the groups was checked using Microvolume Spectrophotometers (Nanodrop) followed by RT-PCR targeting E-gene and RNaseP target. The results showed that the purity index of extracted RNA of untreated pooled specimens was inferior to isopropyl alcohol-treated templates, which was observed to be 85% sensitivity and 100% specificity. The average Cq (E gene) in the unpurified and purified pool RNA group was 34.66 and 31.48, respectively. The nanodrop data suggested that purified RNA concentration was significantly increased with an average value of 24.73 ± 1.49   ng / uL , which might be the reason for high sensitivity and specificity. Thus, this group testing of SARS-CoV-2 cases using pools of 5 individual samples would be the best alternative for saving molecular reagents, personnel time, and can increase the overall testing capacity. However, purity of RNA is one of the important determinants to procure unfailing results, thus, this additional purification step must be included in the protocol after RNA has been extracted using commercially available kit before performing qRT-PCR.

scholarly journals Self-collected gargle specimen as a patient-friendly sample collection method for COVID-19 diagnosis in a population context

2021 ◽  
Author(s):  
Revata Utama ◽  
Rebriarina Hapsari ◽  
Iva Puspitasari ◽  
Desvita Sari ◽  
Meita Hendrianingtyas ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Room Temperature ◽  
Rna Extraction ◽  
User Preference ◽  
Sample Collection ◽  
Rt Pcr ◽  
Collection Method ◽  
Qrt Pcr ◽  
Alternative Specimen ◽  
Temperature Storage

Abstract Scaling up SARS-CoV-2 testing and tracing continues to be plagued with the limitation of the sample collection method, which requires trained healthcare workers to perform and causes discomfort to the patients. In response, we assessed the performance and user preference of gargle specimens for qRT-PCR-based detection of SARS-CoV-2 in Indonesia. Inpatients who had recently been diagnosed with COVID-19 and outpatients who were about to perform qRT-PCR testing were asked to provide nasopharyngeal and oropharyngeal (NPOP) swabs and self-collected gargle specimens. We demonstrated that self-collected gargle specimens can be an alternative specimen to detect SARS-CoV-2 and the viral RNA remained stable for 31 days at room temperature storage. The developed method was validated for use on multiple RNA extraction kits and commercially available COVID-19 RT-PCR kits. Our developed method achieved a sensitivity of 91.38% when compared to paired NPOP swab specimens (Ct < 35), with 97.10% of patients preferring the self-collected gargle method.

scholarly journals A faster and less costly alternative for RNA extraction of SARS-CoV-2 using proteinase k treatment followed by thermal shock

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248885
Author(s):  
Adolfo Marcelo Ñique ◽  
Fiorella Coronado-Marquina ◽  
Jairo Andrés Mendez Rico ◽  
María Paquita García Mendoza ◽  
Nancy Rojas-Serrano ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Real Time ◽  
Internal Control ◽  
Rna Extraction ◽  
Cost Effective ◽  
Proteinase K ◽  
Rt Pcr ◽  
Critical Material ◽  
Proteinase K Treatment ◽  
Commercial Kit

One of the biggest challenges during the pandemic has been obtaining and maintaining critical material to conduct the increasing demand for molecular tests. Sometimes, the lack of suppliers and the global shortage of these reagents, a consequence of the high demand, make it difficult to detect and diagnose patients with suspected SARS-CoV-2 infection, negatively impacting the control of virus spread. Many alternatives have enabled the continuous processing of samples and have presented a decrease in time and cost. These measures thus allow broad testing of the population and should be ideal for controlling the disease. In this sense, we compared the SARS-CoV-2 molecular detection effectiveness by Real time RT-PCR using two different protocols for RNA extraction. The experiments were conducted in the National Institute of Health (INS) from Peru. We compared Ct values average (experimental triplicate) results from two different targets, a viral and internal control. All samples were extracted in parallel using a commercial kit and our alternative protocol–samples submitted to proteinase K treatment (3 μg/μL, 56°C for 10 minutes) followed by thermal shock (98°C for 5 minutes followed by 4°C for 2 minutes); the agreement between results was 100% in the samples tested. In addition, we compared the COVID-19 positivity between six epidemiological weeks: the initial two in that the Real time RT-PCR reactions were conducted using RNA extracted by commercial kit, followed by two other using RNA obtained by our kit-free method, and the last two using kit once again; they did not differ significantly. We concluded that our in-house method is an easy, fast, and cost-effective alternative method for extracting RNA and conducing molecular diagnosis of COVID-19.

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