Micro/nanofluidic devices for DNA/RNA detection and separation

2022 ◽  
pp. 85-107
Author(s):  
Nidhi Verma ◽  
Sakshi Walia ◽  
Alok Pandya
Keyword(s):  
Rna Detection ◽  
Nanofluidic Devices ◽  
Detection And Separation

scholarly journals Seroprevalence of Anti-SARS-CoV-2 IgG and IgM among Adults over 65 Years Old in the South of Italy

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 483
Author(s):  
Immacolata Polvere ◽  
Alfredina Parrella ◽  
Giovanna Casamassa ◽  
Silvia D’Andrea ◽  
Annamaria Tizzano ◽  
...  
Keyword(s):  
Antibody Response ◽  
Immunoglobulin M ◽  
Molecular Testing ◽  
Elisa Assay ◽  
The South ◽  
Serum Samples ◽  
Serological Screening ◽  
Rna Detection ◽  
In Vitro Diagnostic

SARS-CoV-2 is a zoonotic betacoronavirus associated with worldwide transmission of COVID-19 disease. By the beginning of March, WHO reported about 113,820,000 confirmed cases including more than 2,527,000 deaths all over the world. However, the true extent of virus circulation or its real infection/fatality ratio is not well-estimated due to the huge portion of asymptomatic infections. In this observational study, we have estimated the prevalence of specific immunoglobulin M and G directed towards SARS-CoV-2 antigen in a cohort of 1383 adult volunteers aged over 65 years old, living in the district of Benevento, in the South of Italy. Serological screening was carried out on capillary blood in September 2020, seven months after pandemic outbreak in Italy, to evaluate virus circulation and antibody response among elderly adults, in which severe symptoms due to viral infection are more common. The overall seroprevalence of anti-SARS-CoV-2 antibodies was 4.70% (CI 3.70%–5.95%) with no statistically significant differences between sexes. Among these, 69.69% (CI 55.61%–77.80%) tested positive to IgM, 23.08% (CI 14.51%–34.64%) to IgG and 9.23% (CI 4.30%–18.71%) was positive for both. All patients that were positive to IgM underwent molecular testing through RT-qPCR on oral-rhino pharyngeal swabs and only one specimen was positive for SARS-CoV-2 RNA detection. Instead, the presence of IgG from screened volunteers was confirmed by re-testing serum samples using both an ELISA assay validated for in vitro diagnostic use (IVD) and a recently published synthetic peptide-based ELISA assay. In conclusion, our report suggests that (1) early restrictions were successful in limiting COVID-19 diffusion in the district of Benevento; (2) rapid serological analysis is an ideal testing for both determining real seroprevalence and massive screening, whereas detection of viral RNA remains a gold standard for identification of infected patients; (3) even among people without COVID-19 related symptoms, the antibody response against SARS-CoV-2 antigens has individual features.

scholarly journals Optimization of Nanofluidic Devices for Geometry‐Induced Electrostatic Trapping (Part. Part. Syst. Charact. 2/2021)

2021 ◽  
Vol 38 (2) ◽  
pp. 2170003
Author(s):  
Deepika Sharma ◽  
Roderick Y. H. Lim ◽  
Thomas Pfohl ◽  
Yasin Ekinci
Keyword(s):  
Nanofluidic Devices ◽  
Electrostatic Trapping

scholarly journals Superiority of MALDI-TOF Mass Spectrometry over Real-Time PCR for SARS-CoV-2 RNA Detection

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 730
Author(s):  
Magda Rybicka ◽  
Ewa Miłosz ◽  
Krzysztof Piotr Bielawski
Keyword(s):  
Mass Spectrometry ◽  
Gold Standard ◽  
Viral Genome ◽  
False Negative ◽  
Rt Pcr ◽  
Rna Detection ◽  
Maldi Tof ◽  
Negative Results ◽  
False Negative Results ◽  
Pcr Test

At present, the RT-PCR test remains the gold standard for early diagnosis of SARS-CoV-2. Nevertheless, there is growing evidence demonstrating that this technique may generate false-negative results. Here, we aimed to compare the new mass spectrometry-based assay MassARRAY® SARS-CoV-2 Panel with the RT-PCR diagnostic test approved for clinical use. The study group consisted of 168 suspected patients with symptoms of a respiratory infection. After simultaneous analysis by RT-PCR and mass spectrometry methods, we obtained discordant results for 17 samples (10.12%). Within fifteen samples officially reported as presumptive positive, 13 were positive according to the MS-based assay. Moreover, four samples reported by the officially approved RT-PCR as negative were positive in at least one MS assay. We have successfully demonstrated superior sensitivity of the MS-based assay in SARS-CoV-2 detection, showing that MALDI-TOF MS seems to be ideal for the detection as well as discrimination of mutations within the viral genome.

scholarly journals Noncanonical crRNAs derived from host transcripts enable multiplexable RNA detection by Cas9

Science ◽  
2021 ◽  
pp. eabe7106
Author(s):  
Chunlei Jiao ◽  
Sahil Sharma ◽  
Gaurav Dugar ◽  
Natalia L. Peeck ◽  
Thorsten Bischler ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Genetic Material ◽  
Simultaneous Detection ◽  
Type Ii ◽  
Rna Detection ◽  
Single Base ◽  
Dna Targeting ◽  
Single Base Resolution ◽  
Rna Complexes

CRISPR-Cas systems recognize foreign genetic material using CRISPR RNAs (crRNAs). In Type II systems, a trans-activating crRNA (tracrRNA) hybridizes to crRNAs to drive their processing and utilization by Cas9. While analyzing Cas9-RNA complexes from Campylobacter jejuni, we discovered tracrRNA hybridizing to cellular RNAs, leading to formation of “noncanonical” crRNAs capable of guiding DNA targeting by Cas9. Our discovery inspired the engineering of reprogrammed tracrRNAs that link the presence of any RNA-of-interest to DNA targeting with different Cas9 orthologs. This capability became the basis for a multiplexable diagnostic platform termed LEOPARD (Leveraging Engineered tracrRNAs and On-target DNAs for PArallel RNA Detection). LEOPARD allowed simultaneous detection of RNAs from different viruses in one test and distinguished SARS-CoV-2 and its D614G variant with single-base resolution in patient samples.

Sign in / Sign up

Export Citation Format

Share Document