A clinical specimen collection and transport medium for molecular diagnostic and genomic applications

2010 ◽  
Vol 139 (11) ◽  
pp. 1764-1773 ◽  
Author(s):  
L. T. DAUM ◽  
S. A. WORTHY ◽  
K. C. YIM ◽  
M. NOGUERAS ◽  
R. F. SCHUMAN ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Real Time ◽  
Genetic Characterization ◽  
Clinical Specimen ◽  
Molecular Transport ◽  
Cold Chain ◽  
Molecular Diagnostic ◽  
Rt Pcr ◽  
Transport Medium ◽  
Specimen Collection

SUMMARYPathogen detection and genetic characterization has dramatically changed in recent years. Clinical laboratories are transitioning from traditional culture and primer-specific sequencing to more robust and rapid nucleic acid testing such as real-time PCR and meta-genomic characterization, respectively. Specimen collection is the first step in any downstream molecular diagnostic procedure. PrimeStore Molecular Transport Medium (MTM) is an optimized blend of nucleic acid stabilizing reagents that includes a non-specific internal positive control that can be amplified using real-time RT–PCR for tracking the integrity of a specimen from the point of collection to detection. PrimeStore MTM is shown here to effectively kill pathogens, including highly pathogenic H5 influenza virus, inactivate nucleases and to protect and preserve released RNA at ambient temperature for up to 30 days for downstream real-time and traditional RT–PCR detection and genetic characterization. PrimeStore MTM is also compatible with a variety of commercial extraction kits. PrimeStore is suited for routine clinical specimens and has added utility for field collection in remote areas, triage centres, border crossings and during pandemics where cold-chain, transport, and dissemination of potentially infectious pathogens are a concern.

scholarly journals Utility of Nucleic Acid Extraction Free COVID-19 Real Time PCR Protocol in Resource Limited Setting: A Pilot Study

2021 ◽  
Author(s):  
Santosh Karade ◽  
Pratik Thosani ◽  
Prashant Patil ◽  
Kavita Bala Anand ◽  
Sourav Sen ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Pilot Study ◽  
Real Time ◽  
Gold Standard ◽  
Rna Extraction ◽  
Molecular Diagnostic ◽  
Acid Extraction ◽  
Rt Pcr ◽  
Nucleic Acid Extraction ◽  
Resource Limited

Introduction: Coronavirus Disease (COVID-19), a respiratory infection, caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, Hubei province, China in December 2019. Alarming increase in the number of cases has put tremendous pressure on existing health resources. Real Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR), a molecular diagnostic method, is considered gold standard for diagnosis of SARS-CoV-2 infection. It involves RNA extraction as the preliminary step. Innovations to cut down cost and time involved in SARS-CoV-2 testing are need of hour. Aim: The aim of this study was to assess the feasibility of Nucleic Acid Extraction Free (NEF) protocol for COVID-19 diagnosis in resource limited settings. Materials and Methods: In this pilot study a panel of 148 Nasopharyngeal (NP) samples was subjected to the novel NEF RT-PCR protocol and results were compared to gold standard RT-PCR on RNA extracted from NP specimen. The cycle threshold value for each target was tabulated in MS Excel Spreadsheet and data analysis was performed using Statistical Package for Social Sciences (SPSS) software version 15.0. Results: Out of 148 collected samples, 120 showed amplification of E and RdRp targets by RNA extraction-based RT-PCR. Overall sensitivity and specificity observed for NEF protocol was 43.94% and 96.42%, respectively. Conclusion: Further refinement in the protocol would be required to improve the sensitivity of NEF protocol and widespread use in laboratories.

scholarly journals Cases Report of Cured Novel Coronavirus-infected Pneumonia Patients with Viral Nucleic Acid Test Positive in Fecal Specimens

2020 ◽  
Author(s):  
Mei Han ◽  
Jingbo Zou ◽  
Wenguang Tian ◽  
Xiaoyu Wei ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Molecular Diagnostic ◽  
Clinical Practices ◽  
Rt Pcr ◽  
Viral Nucleic Acid ◽  
Nucleic Acid Test ◽  
Assessment Standard ◽  
Novel Coronavirus ◽  
Acid Test ◽  
Respiratory Specimens

Abstract Background: The outbreak of the novel coronavirus in China (COVID-19) represents a significant and urgent threat to global health. We report here five cases of COVID-19 infection patients in our clinical practices who are medically stable and presumed to successfully “cleared” the virus after antiviral treatments. Case presentation: The clinical evaluation depends on the viral nucleic acid test in respiratory specimens by real-time PCR reverse transcription (RT-PCR) assays according to the authorized guidance. We found that the stool samples of these cured patients remain positive in RT-PCR assay while the virus is undetectable in respiratory specimens. RT-PCR molecular diagnostic assay was designed to specifically detect the presence of viral RNA. Thus, the positive result in the fecal specimens implies the existence of viable virions with the patients. Conclusions: This highlights the importance to look closely at the assessment standard of medical treatment, as well as the need for reevaluation of the criteria for the initial screening, prevention, and care of patients with this emerging infection.

scholarly journals A Cold Chain-Independent Specimen Collection and Transport Medium Improves Diagnostic Sensitivity and Minimizes Biosafety Challenges of COVID-19 Molecular Diagnosis

2021 ◽  
Author(s):  
Vikram Saini ◽  
Priya Kalra ◽  
Manish Sharma ◽  
Chhavi Rai ◽  
Vikas Saini ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Urban Population ◽  
Viral Transmission ◽  
Diagnostic Sensitivity ◽  
Cold Chain ◽  
Transport Medium ◽  
Contagious Nature ◽  
Specimen Collection ◽  
Rural And Urban ◽  
Global Population

Approximately forty-four percent of the global population lives in villages, including 59% in Africa ( https://unhabitat.org/World%20Cities%20Report%202020 ). The fast-evolving nature of SARS-CoV-2 and its extremely contagious nature warrant early and accurate COVID-19 diagnostics across rural and urban population as a key to prevent viral transmission. Unfortunately, lack of adequate infrastructure, including the availability of biosafety-compliant facilities and an end-to-end cold chain availability for COVID-19 molecular diagnosis, limits the accessibility of testing in these countries.

scholarly journals Lyophilized Matrix Containing Ready-to-Use Primers and Probe Solutions for Standardization of Real-Time PCR and RT-qPCR Diagnostics

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 7
Author(s):  
Remi N Charrel ◽  
Laurence Thirion
Keyword(s):  
Real Time ◽  
Molecular Techniques ◽  
Cold Chain ◽  
Rt Pcr ◽  
Emerging Viruses ◽  
Valley Fever ◽  
Term Stability ◽  
E Gene ◽  
Long Term Stability

Real-time molecular techniques have become the reference methods for the direct diagnosis of pathogens. The reduction of steps is a key factor in order to decrease the risk of human errors resulting in invalid series and delayed results. We describe here a process involving the preparation of oligonucleotide primers and a hydrolysis probe in a single tube at predefined optimized concentrations that are stabilized via lyophilization (Lyoph-P&P). Lyoph-P&P was compared to the classic protocol using extemporaneously prepared liquid reagents, assaying (i) sensitivity, (ii) long-term stability at 4 °C, and (iii) long-term stability at 37 °C, mimicking transportation without a cold chain. Two previously published molecular assays were selected for this study. They target two emerging viruses that are listed on the blueprint of the WHO to be considered for preparedness and response actions: chikungunya virus (CHIKV) and Rift Valley fever phlebovirus (RVFV). The results of our study demonstrate that (i) Lyoph-P&P is stable for at least four days at 37 °C, supporting shipping without the need of a cold chain, (ii) Lyoph-P&P rehydrated solution is stable at 4 °C for at least two weeks, (iii) the sensitivity observed with Lyoph-P&P is at least equal to, and often better than, that observed with liquid formulation, and (iv) the validation of results observed with low-copy specimens is rendered easier by higher fluorescence levels. In conclusion, Lyoph-P&P holds several advantages over extemporaneously prepared liquid formulations and merits consideration as a novel real-time molecular assay for implementation into a laboratory with routine diagnostic activity. Since the meeting, this concept has been applied to the COVID-19 situation: two diagnostic assays (E gene and RdRp) have been developed and can be ordered on the European Virus Archive catalog (https://www.european-virus-archive.com/detection-kit/lyophilized-primers-and-probe-rt-pcr-2019-ncov-e-gene; https://www.european-virus-archive.com/detection-kit/lyophilized-primers-and-probe-rt-pcr-sars-cov-2-rdrp-gene).

scholarly journals Development, Evaluation of the PNA RT-LAMP Assay for Rapid Molecular Detection of SARS-CoV-2

2021 ◽  
Author(s):  
Chinbayar Bat-Ochir ◽  
Yeon-Sook Kim ◽  
Han Gyeul Kim ◽  
See Sok Lee ◽  
Han Woo Lee ◽  
...  
Keyword(s):  
Real Time ◽  
Lamp Assay ◽  
Study Data ◽  
Molecular Diagnostic ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Clinical Sensitivity ◽  
Clinical Accuracy ◽  
Absolute Detection Limit ◽  
Development Evaluation

Abstract Dual-labeled PNA probe used RT-LAMP molecular rapid assay targeting SARS-CoV-2 ORF1ab and N genes was developed, and the analytical, clinical performances for detection of SARS-CoV-2 RNA extracted from clinical nasopharyngeal swab specimens were evaluated in this study. Data showed that this assay is highly specific for SARS-CoV-2, and the absolute detection limit is 1 genomic copy per microliter of viral RNA which can be considered to be comparable to gold-standard molecular diagnostic method real-time reverse transcriptase PCR. Both clinical sensitivity and specificity against a commercial real-time RT-PCR assay were determined as identical. In conclusion, the PNA RT-LAMP assay showed high analytical and clinical accuracy which are identical to real-time RT-PCR which has been routinely used for the detection of SARS-CoV-2.

scholarly journals Optimization of Real-time Reverse Transcriptase Polymerase Chain Reaction for Detection of Dengue Virus

2020 ◽  
pp. 1-7
Author(s):  
Kaunara A. Azizi ◽  
Arnold J. Ndaro ◽  
Athanasia Maro ◽  
Adonira Saro ◽  
Reginald A. Kavishe
Keyword(s):  
Polymerase Chain Reaction ◽  
Nucleic Acid ◽  
Dengue Virus ◽  
Reverse Transcriptase ◽  
Real Time ◽  
Acid Extraction ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Reliable Technique ◽  
Polymerase Chain

Aims: This study was set to optimize conditions for real time reverse transcriptase polymerase chain reaction (RT-PCR) for detection of dengue virus by using rapid and simple nucleic acid extraction method. Methodology: One step and two step real time RT-PCR were evaluated in different PCR thermocyclers. Extraction of viral RNA was done by using a simple boom method. Results: The real time RT-PCR technique was successfully optimized using simple and rapid method for purification of nucleic acid, ‘boom method’. The technique works better when performed in a two-step procedure and can works well with all range of real time PCR machines. The optimized real time RT-PCR used in the present study is a valuable and reliable technique for routine diagnosis of dengue. Further investigation on the cost effectiveness in adopting this technique for routine screening and monitoring of the dengue infection should be done.

scholarly journals Real-Time Detection of Noroviruses in Surface Water by Use of a Broadly Reactive Nucleic Acid Sequence-Based Amplification Assay

2006 ◽  
Vol 72 (8) ◽  
pp. 5349-5358 ◽  
Author(s):  
Saskia A. Rutjes ◽  
Harold H. J. L. van den Berg ◽  
Willemijn J. Lodder ◽  
Ana Maria de Roda Husman
Keyword(s):  
Nucleic Acid ◽  
Real Time ◽  
Water Samples ◽  
Rna Extraction ◽  
Sewage Treatment ◽  
Rdrp Gene ◽  
Nucleic Acid Sequence ◽  
Viral Gastroenteritis ◽  
Rt Pcr ◽  
Inhibitory Factors

ABSTRACT Noroviruses are the most common agents causing outbreaks of viral gastroenteritis. Outbreaks originating from contaminated drinking water and from recreational waters have been described. Due to a lack of cell culture systems, noroviruses are detected mostly by molecular methods. Molecular detection assays for viruses in water are often repressed by inhibitory factors present in the environment, like humic acids and heavy metals. To study the effect of environmental inhibitors on the performance of nucleic acid sequence-based amplification (NASBA), we developed a real-time norovirus NASBA targeting part of the RNA-dependent RNA polymerase (RdRp) gene. Specificity of the assay was studied with 33 divergent clones that contained part of the targeted RdRp gene of noroviruses from 15 different genogroups. Viral RNA originated from commercial oysters, surface waters, and sewage treatment plants in The Netherlands. Ninety-seven percent of the clones derived from human noroviruses were detected by real-time NASBA. Two clones containing animal noroviruses were not detected by NASBA. We compared the norovirus detection by real-time NASBA with that by conventional reverse transcriptase PCR (RT-PCR) with large-volume river water samples and found that inhibitory factors of RT-PCR had little or no effect on the performance of the norovirus NASBA. This consequently resulted in a higher sensitivity of the NASBA assay than of the RT-PCR. We show that by combining an efficient RNA extraction method with real-time NASBA the sensitivity of norovirus detection in water samples increased at least 100 times, which consequently has implications for the outcome of the infectious risk assessment.

scholarly journals Evaluation of real-time nucleic acid sequence-based amplification for detection of Chikungunya virus in clinical samples

2009 ◽  
Vol 58 (9) ◽  
pp. 1168-1172 ◽  
Author(s):  
J.-N. Telles ◽  
K. Le Roux ◽  
P. Grivard ◽  
G. Vernet ◽  
A. Michault
Keyword(s):  
Nucleic Acid ◽  
Real Time ◽  
Chikungunya Virus ◽  
False Negative ◽  
Nucleic Acid Sequence ◽  
Clinical Samples ◽  
Acid Extraction ◽  
Plasma Samples ◽  
Rt Pcr ◽  
Nucleic Acid Extraction

The Chikungunya virus (CHIKV) is a member of the genus Alphavirus that is transmitted to humans by Aedes mosquitoes. In 2005 and 2006, the Indian Ocean island of La Réunion was hit with an unprecedented CHIKV fever outbreak that infected 300 000 people. In the present study, we describe the evaluation of real-time nucleic acid sequence-based amplification (RT-NASBA) for the detection of CHIKV in clinical samples. A co-extracted and co-amplified chimerical CHIKV RNA sequence was used as an internal control to eliminate false-negative results. The detection threshold of the assay was determined from quantified CHIKV-positive plasma, and estimated to be 200 copies per NASBA reaction. The specificity of the assay was determined using blast analyses and non-cross-reactivity using an O'nyong-nyong virus culture and 250 CHIKV RT-PCR-negative plasma samples. A 100 % specificity was found and no invalid result was obtained, showing the good quality of the nucleic acid extraction. The assay was then evaluated using 252 CHIKV-positive RT-PCR plasma samples. The samples were all tested positive, including those with low viral load. This evaluation showed that the RT-NASBA is a rapid (5 h from sample nucleic acid extraction to detection), sensitive, specific and reliable method for the routine diagnosis of CHIKV in clinical samples.

Sign in / Sign up

Export Citation Format

Share Document