Comparison of approaches for IgG avidity calculation and a new highly sensitive and specific method with broad dynamic range

Background: Cytochrome c is an intermembrane mitochondrial protein that is released to the bloodstream following mitochondrial injury. Methods and results: We developed an electrochemiluminescence immunoassay to measure cytochrome c in human and rat plasma, which showed high sensitivity with broad dynamic range (2-1200 ng/mL in humans and 5-500 ng/mL in rat) and high assay reproducibility (inter-assay coefficient <6% in humans and <10% in rat). In patients after blunt trauma, plasma cytochrome c directly correlated with injury severity. In rats after cardiac resuscitation, plasma cytochrome c inversely correlated with survival and responsiveness to mitochondrial protective interventions. Conclusions: The cytochrome c assays herein presented have high sensitivity, wide dynamic range, and high reproducibility well suited for biomarker of mitochondrial injury.

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Multiplex Assays of Luminex for Identification of COVID-19 Antibodies in Patient Serum: Performance Evaluation and Comparison to ELISA

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa161.201 ◽

2020 ◽

Vol 154 (Supplement_1) ◽

pp. S92-S92

Author(s):

M S Shapiro ◽

X Wang ◽

D R Mendu ◽

A Firpo

Keyword(s):

Dynamic Range ◽

High Titer ◽

Mount Sinai Hospital ◽

Antibody Testing ◽

Luminex Assay ◽

Multiplex Assays ◽

Negative Results ◽

Broad Dynamic Range ◽

Circulating Antibodies ◽

Mount Sinai

Abstract Introduction/Objective Mount Sinai Hospital has received emergency use authorization (EUA) from the FDA for Coronavirus Disease 2019 (COVID-19) antibody testing using ELISA. This serological assay detects and titrates the presence of circulating antibodies to COVID-19. Other platforms have aimed to achieve the credentials of the ELISA instrument, including the multiplex assays of Luminex. The platform is known to have a greater throughput (384 wells vs. 96 wells per microplate) and faster processing speed (8 hours vs. 17 hours). Methods Luminex utilizes beads that couple to the same COVID-19 antigens (mRBD and mSpike) which were utilized for the ELISA assay. The beads are read determining the mean fluorescence intensity (MFI). In order to compare the two methods, our study included 61 patients with COVID-19 at Mount Sinai Hospital, to screen and titrate their sera using Luminex, and to correspond the MFI values with the ELISA titers. Results The Luminex assay has achieved the same level of confidence as ELISA. The 61 patients, representing 30 negatives and 31 positives, are consistently identified as such on both platforms. Our data highlights 32% of patients with a low titer (<1:160), 42% of patients with a high titer (1:160 ~ 1:320), and 26% of patients with a very high titer level (>1:320). These titers correlated well with the MFI values. Based on a cutoff of 80,000 MFI, the sensitivity and specificity of the assay is 98% and 85%, respectively, with no overlapping of MFI between positive and negative results. Conclusion Overall, the study has demonstrated that the Luminex is a strong alternative for the ELISA platform. The Luminex highlights the broad dynamic range with no overlapping between positives and negatives. Migration from ELISA to Luminex, a platform with faster and greater throughput, is therefore, highly desirable.

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A tandem giant magnetoresistance assay for one-shot quantification of clinically relevant concentrations of N-terminal pro-B-type natriuretic peptide in human blood

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-021-03227-5 ◽

2021 ◽

Author(s):

Fanda Meng ◽

Weisong Huo ◽

Jie Lian ◽

Lei Zhang ◽

Xizeng Shi ◽

...

Keyword(s):

Detection Limit ◽

Giant Magnetoresistance ◽

Dynamic Range ◽

Point Of Care ◽

Sample Volume ◽

Small Sample ◽

Broad Dynamic Range ◽

Gmr Sensors ◽

Gmr Sensor ◽

Sample Volume Requirement

AbstractWe report a microfluidic sandwich immunoassay constructed around a dual-giant magnetoresistance (GMR) sensor array to quantify the heart failure biomarker NT-proBNP in human plasma at the clinically relevant concentration levels between 15 pg/mL and 40 ng/mL. The broad dynamic range was achieved by differential coating of two identical GMR sensors operated in tandem, and combining two standard curves. The detection limit was determined as 5 pg/mL. The assay, involving 53 plasma samples from patients with different cardiovascular diseases, was validated against the Roche Cobas e411 analyzer. The salient features of this system are its wide concentration range, low detection limit, small sample volume requirement (50 μL), and the need for a short measurement time of 15 min, making it a prospective candidate for practical use in point of care analysis.

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Engineering Cyanobacterial Cell Morphology for Enhanced Recovery and Processing of Biomass

Applied and Environmental Microbiology ◽

10.1128/aem.00053-17 ◽

2017 ◽

Vol 83 (9) ◽

Cited By ~ 15

Author(s):

Adam Jordan ◽

Jenna Chandler ◽

Joshua S. MacCready ◽

Jingcheng Huang ◽

Katherine W. Osteryoung ◽

...

Keyword(s):

Cell Division ◽

Cell Morphology ◽

Dynamic Range ◽

Enhanced Recovery ◽

Downstream Processing ◽

Crop Species ◽

Content Type ◽

Alternative Crop ◽

Cell Harvesting ◽

Broad Dynamic Range

ABSTRACT Cyanobacteria are emerging as alternative crop species for the production of fuels, chemicals, and biomass. Yet, the success of these microbes depends on the development of cost-effective technologies that permit scaled cultivation and cell harvesting. Here, we investigate the feasibility of engineering cell morphology to improve biomass recovery and decrease energetic costs associated with lysing cyanobacterial cells. Specifically, we modify the levels of Min system proteins in Synechococcus elongatus PCC 7942. The Min system has established functions in controlling cell division by regulating the assembly of FtsZ, a tubulin-like protein required for defining the bacterial division plane. We show that altering the expression of two FtsZ-regulatory proteins, MinC and Cdv3, enables control over cell morphology by disrupting FtsZ localization and cell division without preventing continued cell growth. By varying the expression of these proteins, we can tune the lengths of cyanobacterial cells across a broad dynamic range, anywhere from an ∼20% increased length (relative to the wild type) to near-millimeter lengths. Highly elongated cells exhibit increased rates of sedimentation under low centrifugal forces or by gravity-assisted settling. Furthermore, hyperelongated cells are also more susceptible to lysis through the application of mild physical stress. Collectively, these results demonstrate a novel approach toward decreasing harvesting and processing costs associated with mass cyanobacterial cultivation by altering morphology at the cellular level. IMPORTANCE We show that the cell length of a model cyanobacterial species can be programmed by rationally manipulating the expression of protein factors that suppress cell division. In some instances, we can increase the size of these cells to near-millimeter lengths with this approach. The resulting elongated cells have favorable properties with regard to cell harvesting and lysis. Furthermore, cells treated in this manner continue to grow rapidly at time scales similar to those of uninduced controls. To our knowledge, this is the first reported example of engineering the cell morphology of cyanobacteria or algae to make them more compatible with downstream processing steps that present economic barriers to their use as alternative crop species. Therefore, our results are a promising proof-of-principle for the use of morphology engineering to increase the cost-effectiveness of the mass cultivation of cyanobacteria for various sustainability initiatives.

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Plasmonic substrates for multiplexed protein microarrays with femtomolar sensitivity and broad dynamic range

Nature Communications ◽

10.1038/ncomms1477 ◽

2011 ◽

Vol 2 (1) ◽

Cited By ~ 166

Author(s):

Scott M. Tabakman ◽

Lana Lau ◽

Joshua T. Robinson ◽

Jordan Price ◽

Sarah P. Sherlock ◽

...

Keyword(s):

Dynamic Range ◽

Protein Microarrays ◽

Broad Dynamic Range

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A FRET based pH probe with a broad working range applicable to referenced ratiometric dual wavelength and luminescence lifetime read out

Chemical Communications ◽

10.1039/c5cc00144g ◽

2015 ◽

Vol 51 (28) ◽

pp. 6145-6148 ◽

Cited By ~ 22

Author(s):

Robert J. Meier ◽

Johann M. B. Simbürger ◽

Tero Soukka ◽

Michael Schäferling

Keyword(s):

Dynamic Range ◽

Dual Wavelength ◽

Luminescence Lifetime ◽

Ph Sensing ◽

Ph Probe ◽

Broad Dynamic Range ◽

Europium Chelate ◽

Ratiometric Ph Sensing

A FRET system composed of a europium chelate and carboxynaphthofluorescein enables ratiometric pH sensing with an exceptionally broad dynamic range.

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Fluorescence lifetime-based biosensing of zinc: Origin of the broad dynamic range

Journal of Fluorescence ◽

10.1007/bf00727528 ◽

1995 ◽

Vol 5 (2) ◽

pp. 123-130 ◽

Cited By ~ 19

Author(s):

Richard B. Thompson ◽

Marcia W. Patchan

Keyword(s):

Fluorescence Lifetime ◽

Dynamic Range ◽

Broad Dynamic Range

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Highly sensitive dual mode electrochemical platform for microRNA detection

Scientific Reports ◽

10.1038/srep36719 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 38

Author(s):

Pawan Jolly ◽

Marina R. Batistuti ◽

Anna Miodek ◽

Pavel Zhurauski ◽

Marcelo Mulato ◽

...

Keyword(s):

Nucleic Acids ◽

Dynamic Range ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Dual Mode ◽

Electrode Surfaces ◽

Microrna Detection ◽

Highly Sensitive ◽

Detection Mode ◽

Amplification Strategy

Abstract MicroRNAs (miRNAs) play crucial regulatory roles in various human diseases including cancer, making them promising biomarkers. However, given the low levels of miRNAs present in blood, their use as cancer biomarkers requires the development of simple and effective analytical methods. Herein, we report the development of a highly sensitive dual mode electrochemical platform for the detection of microRNAs. The platform was developed using peptide nucleic acids as probes on gold electrode surfaces to capture target miRNAs. A simple amplification strategy using gold nanoparticles has been employed exploiting the inherent charges of the nucleic acids. Electrochemical impedance spectroscopy was used to monitor the changes in capacitance upon any binding event, without the need for any redox markers. By using thiolated ferrocene, a complementary detection mode on the same sensor was developed where the increasing peaks of ferrocene were recorded using square wave voltammetry with increasing miRNA concentration. This dual-mode approach allows detection of miRNA with a limit of detection of 0.37 fM and a wide dynamic range from 1 fM to 100 nM along with clear distinction from mismatched target miRNA sequences. The electrochemical platform developed can be easily expanded to other miRNA/DNA detection along with the development of microarray platforms.

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