Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Optofluidic multiplex detection of single SARS-CoV-2 and influenza A antigens using a novel bright fluorescent probe assay.

ABSTRACT: The urgency for the development of a sensitive, specific, and rapid point-of-care diagnostic test has deepened during the ongoing COVID-19 pandemic. Here, we introduce an ultrasensitive chip-based antigen test with single protein biomarker sensitivity for the differentiated detection of both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A antigens in nasopharyngeal swab samples at diagnostically relevant concentrations. The single-antigen assay is enabled by synthesizing a brightly fluorescent reporter probe, which is incorporated into a bead-based solid-phase extraction assay centered on an antibody sandwich protocol for the capture of target antigens. After optimization of the probe release for detection using ultraviolet light, the full assay is validated with both SARS-CoV-2 and influenza A antigens from clinical nasopharyngeal swab samples (PCR-negative spiked with target antigens). Spectrally multiplexed detection of both targets is implemented by multispot excitation on a multimode interference waveguide platform, and detection at 30 ng/mL with single-antigen sensitivity is reported.

SUBMITTER: Stambaugh A

PROVIDER: S-EPMC8158013 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Systematic evaluation of SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay.

Project description:ObjectiveThe COVID-19 pandemic poses an immense need for accurate, sensitive and high-throughput clinical tests, and serological assays are needed for both overarching epidemiological studies and evaluating vaccines. Here, we present the development and validation of a high-throughput multiplex bead-based serological assay.MethodsMore than 100 representations of SARS-CoV-2 proteins were included for initial evaluation, including antigens produced in bacterial and mammalian hosts as well as synthetic peptides. The five best-performing antigens, three representing the spike glycoprotein and two representing the nucleocapsid protein, were further evaluated for detection of IgG antibodies in samples from 331 COVID-19 patients and convalescents, and in 2090 negative controls sampled before 2020.ResultsThree antigens were finally selected, represented by a soluble trimeric form and the S1-domain of the spike glycoprotein as well as by the C-terminal domain of the nucleocapsid. The sensitivity for these three antigens individually was found to be 99.7%, 99.1% and 99.7%, and the specificity was found to be 98.1%, 98.7% and 95.7%. The best assay performance was although achieved when utilising two antigens in combination, enabling a sensitivity of up to 99.7% combined with a specificity of 100%. Requiring any two of the three antigens resulted in a sensitivity of 99.7% and a specificity of 99.4%.ConclusionThese observations demonstrate that a serological test based on a combination of several SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay.

| S-EPMC8288725 | biostudies-literature

Conversion of red fluorescent protein into a bright blue probe.

Project description:We used a red chromophore formation pathway, in which the anionic red chromophore is formed from the neutral blue intermediate, to suggest a rational design strategy to develop blue fluorescent proteins with a tyrosine-based chromophore. The strategy was applied to red fluorescent proteins of the different genetic backgrounds, such as TagRFP, mCherry, HcRed1, M355NA, and mKeima, which all were converted into blue probes. Further improvement of the blue variant of TagRFP by random mutagenesis resulted in an enhanced monomeric protein, mTagBFP, characterized by the substantially higher brightness, the faster chromophore maturation, and the higher pH stability than blue fluorescent proteins with a histidine in the chromophore. The detailed biochemical and photochemical analysis indicates that mTagBFP is the true monomeric protein tag for multicolor and lifetime imaging, as well as the outstanding donor for green fluorescent proteins in Förster resonance energy transfer applications.

| S-EPMC2585067 | biostudies-literature

Clinical evaluation of AusDiagnostics SARS-CoV-2 multiplex tandem PCR assay.

Project description:BACKGROUND:In the context of the pandemic, the rapid emergency use authorisation of diagnostic assays for SARS-CoV-2 has meant there are few peer-reviewed published studies of clinical performance of commercial assays. AIMS:To evaluate the clinical performance of AusDiagnostics respiratory multiplex tandem PCR assay including SARS-CoV-2. METHODS:We reviewed the results following implementation of AusDiagnostics respiratory multiplex tandem PCR assay including SARS-CoV-2, and compared with an in-house RT-PCR assay at our State Reference Laboratory. RESULTS:Initial validation using AusDiagnostics coronavirus multiplex tandem PCR assay including SARS-CoV-2 demonstrated good concordance with the State Reference Laboratory. After implementing the AusDiagnostics respiratory multiplex tandem PCR assay including SARS-CoV-2, we tested 7839 samples. 127 samples in which SARS-CoV-2 was detected using the AusDiagnostics assay were referred for testing at the State Reference Laboratory, with concordant results in 118/127 (92.9%) of samples. After resolution of discrepancies, 125/127 (98.4%) of AusDiagnostics results were determined to be true positive results. Out of 7839 samples tested for SARS-CoV-2 during this period, only 2 tests (0.02%) were indeterminate results. CONCLUSION:The AusDiagnostics respiratory MT-PCR assay is a reliable assay for detection of SARS-CoV-2.

| S-EPMC7236671 | biostudies-literature

ReScan, a Multiplex Diagnostic Pipeline, Pans Human Sera for SARS-CoV-2 Antigens.

Project description:Comprehensive understanding of the serological response to SARS-CoV-2 infection is important for both pathophysiologic insight and diagnostic development. Here, we generate a pan-human coronavirus programmable phage display assay to perform proteome-wide profiling of coronavirus antigens enriched by 98 COVID-19 patient sera. Next, we use ReScan, a method to efficiently sequester phage expressing the most immunogenic peptides and print them onto paper-based microarrays using acoustic liquid handling, which isolates and identifies nine candidate antigens, eight of which are derived from the two proteins used for SARS-CoV-2 serologic assays: spike and nucleocapsid proteins. After deployment in a high-throughput assay amenable to clinical lab settings, these antigens show improved specificity over a whole protein panel. This proof-of-concept study demonstrates that ReScan will have broad applicability for other emerging infectious diseases or autoimmune diseases that lack a valid biomarker, enabling a seamless pipeline from antigen discovery to diagnostic using one recombinant protein source.

| S-EPMC7513813 | biostudies-literature

Simultaneous evaluation of antibodies that inhibit SARS-CoV-2 variants via multiplex assay.

Project description:The SARS-CoV-2 receptor binding domain (RBD) is both the principal target of neutralizing antibodies and one of the most rapidly evolving domains, which can result in the emergence of immune escape mutations, limiting the effectiveness of vaccines and antibody therapeutics. To facilitate surveillance, we developed a rapid, high-throughput, multiplex assay able to assess the inhibitory response of antibodies to 24 RBD natural variants simultaneously. We demonstrate how this assay can be implemented as a rapid surrogate assay for functional cell-based serological methods to measure the SARS-CoV-2 neutralizing capacity of antibodies at the angiotensin-converting enzyme 2-RBD (ACE2-RBD) interface. We describe the enhanced affinity of RBD variants N439K, S477N, Q493L, S494P, and N501Y to the ACE2 receptor and demonstrate the ability of this assay to bridge a major gap for SARS-CoV-2 research, informing selection of complementary monoclonal antibody candidates and the rapid identification of immune escape to emerging RBD variants following vaccination or natural infection.

| S-EPMC8409985 | biostudies-literature

A sensitive and affordable multiplex RT-qPCR assay for SARS-CoV-2 detection.

Project description:With the ongoing COVID-19 (Coronavirus Disease 2019) pandemic, caused by the novel coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), there is a need for sensitive, specific, and affordable diagnostic tests to identify infected individuals, not all of whom are symptomatic. The most sensitive test involves the detection of viral RNA using RT-qPCR (quantitative reverse transcription PCR), with many commercial kits now available for this purpose. However, these are expensive, and supply of such kits in sufficient numbers cannot always be guaranteed. We therefore developed a multiplex assay using well-established SARS-CoV-2 targets alongside a human cellular control (RPP30) and a viral spike-in control (Phocine Herpes Virus 1 [PhHV-1]), which monitor sample quality and nucleic acid extraction efficiency, respectively. Here, we establish that this test performs as well as widely used commercial assays, but at substantially reduced cost. Furthermore, we demonstrate >1,000-fold variability in material routinely collected by combined nose and throat swabbing and establish a statistically significant correlation between the detected level of human and SARS-CoV-2 nucleic acids. The inclusion of the human control probe in our assay therefore provides a quantitative measure of sample quality that could help reduce false-negative rates. We demonstrate the feasibility of establishing a robust RT-qPCR assay at approximately 10% of the cost of equivalent commercial assays, which could benefit low-resource environments and make high-volume testing affordable.

| S-EPMC7771873 | biostudies-literature

Multiplex Nucleic Acid Assay of SARS-CoV-2 via a Lanthanide Nanoparticle-Tagging Strategy.

Project description:Early diagnosis, early isolation, and early treatment are efficient solutions to control the COVID-19 pandemic. To achieve the accurate early diagnosis of SARS-CoV-2, a multiplex detection strategy is required for the cross-validation to solve the problem of "false negative" of the existing gold standard assay. Here, we present a multicomponent nucleic acid assay platform for SARS-CoV-2 detection based on lanthanide nanoparticle (LnNP)-tagging strategy. For targeting SARS-CoV-2's RNA fragments ORF1ab gene, RdRp gene, and E gene, three LnNP probes can be used simultaneously to identify three sites in one sample through elemental mass spectrometry detection with limits of detection of 1.2, 1.3, and 1.3 fmol, respectively. With the multisite cross-validation, we envision that this multiplex and sensitive detection platform may provide an effective strategy for SARS-CoV-2 fast screening with a high accuracy.

| S-EPMC8442555 | biostudies-literature

A multiplex serological assay for the characterization of IgG immune response to SARS-CoV-2.

Project description:In the fight against SARS-COV-2, the development of serological assays based on different antigenic domains represent a versatile tool to get a comprehensive picture of the immune response or differentiate infection from vaccination beyond simple diagnosis. Here we use a combination of the Nucleoprotein (NP), the Spike 1 (S1) and Spike 2 (S2) subunits, and the receptor binding domain (RBD) and N-terminal domain (NTD) of the Spike antigens from the CoViDiag® multiplex IgG assay, to follow the immune response to SARS-CoV-2 infection over a long time period and depending on disease severity. Using a panel of 209 sera collected from 61 patients up to eight months after infection, we observed that most patients develop an immune response against multiple viral epitope, but anti-S2 antibodies seemed to last longer. For all the tested IgGs, we have found higher responses for hospitalized patients than for non-hospitalized ones. Moreover the combination of the five different IgG responses increased the correlation to the neutralizing antibody titers than if considered individually. Multiplex immunoassays have the potential to improve diagnostic performances, especially for ancient infection or mild form of the disease presenting weaker antibody responses. Also the combined detection of anti-NP and anti-Spike-derived domains can be useful to differentiate vaccination from viral infection and accurately assess the antibody potential to neutralize the virus.

| S-EPMC8757954 | biostudies-literature

Multiplex assessment of SARS-CoV-2 antibodies improves assay sensitivity and correlation with neutralizing antibodies.

Project description:ObjectivesDetection of antibodies to multiple SARS-CoV-2 antigens in a single assay could increase diagnostic accuracy, differentiate vaccination from natural disease, and aid in retrospective exposure determination. Correlation of binding antibody assessment in clinical assays with neutralizing antibodies is needed to better understand the humoral response to SARS-CoV-2 infection and establish of correlates of protection.MethodsA cohort of 752 samples was used to assess specificity, sensitivity, and comparison to 6 other Conformitè Europëenne serologic assays for the BioRad SARS-CoV-2 IgG multiplex assay which measures receptor binding domain IgG (RBD), spike-S1 IgG (S1), spike-S2 IgG (S2), and nucleocapsid IgG (N). A subset of serial specimens from 14 patients was also tested for neutralizing antibodies (n = 61).ResultsSpecificity for RBD and S1 IgG was 99.4% (n = 170) and 100% for S2 and N IgG (n = 170) in a cohort selected for probable interference. Overall assay concordance with other assays was >93% for IgG and total antibody assays and reached 100% sensitivity for clinical concordance at >14 days as a multiplex assay. RBD and S1 binding antibody positivity demonstrated 79-95% agreement with the presence of neutralizing antibodies.ConclusionsThe BioRad SARS-CoV-2 IgG assay is comparable to existing assays, and achieved 100% sensitivity when all markers were included. The ability to measure antibodies against spike and nucleocapsid proteins simultaneously may be advantageous for complex clinical presentations, epidemiologic research, and in decisions regarding infection prevention strategies. Additional independent validations are needed to further determine binding antibody and neutralizing antibody correlations.

| S-EPMC8387133 | biostudies-literature

An optofluidic temperature probe.

Project description:We report the application of a microfluidic device for semi-contact temperature measurement in picoliter volumes of aqueous media. Our device, a freely positionable multifunctional pipette, operates by a hydrodynamic confinement principle, i.e., by creating a virtual flow cell of micrometer dimensions within a greater aqueous volume. We utilized two fluorescent rhodamines, which exhibit different fluorescent responses with temperature, and made ratiometric intensity measurements. The temperature dependence of the intensity ratio was calibrated and used in a model study of the thermal activation of TRPV1 ion channels expressed in Chinese hamster ovary cells. Our approach represents a practical and robust solution to the specific problem of measuring temperature in biological experiments in vitro, involving highly localized heat generation, for example with an IR-B laser.

| S-EPMC3673084 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data