Q-Plex™ SARS-CoV-2 Human IgG (4-Plex)

Q-Plex SARS-CoV-2 Human IgG (4-Plex)

For measurement of SARS-CoV-2 S1, SARS-CoV-2 S2, Sheep Fc (negative control), Anti-Human IgG (positive control)

  • Species Specificity: Human
  • Validated Sample Type: Human Serum, Plasma
  • Sample Volume Required: Min. 2 µL
  • Estimated Assay Length: 2 hours
  • Intra-Assay Cross-Reactivity: See Assay Validation Below
  • Assay Type: Indirect
  • Detection Method: Chemiluminescent
  • Multiplex Format: 96-well solid plate
  • Catalog #: 691649HU
SARS-CoV-2 IgG Assay (Combined Result from S1 & S2) vs. Molecular COVID-19 Test
N = 576 Confirmed Positive Confirmed Negative
IgG Test Positive 33 0
IgG Test Negative 1 542
The combined S1 & S2 reactive antibody assay demonstrates:
Estimated Sensitivity (PPA) 97%
Estimated Specificity (NPA) 100%
PPV 100%
NPV 100%
SARS-CoV-2 IgG Assay Characteristics
Principle Indirect ELISA
Sample Type Serum, Plasma, Whole Blood
Sample Volume 2 µL
Assay Incubation 2 hours, RT
Total Wash Steps 3
Within Plate Reproducibility 8% CV
Between Plate Reproducibility 10% CV
Analyte Assay Type Calibrator Range Upper Limit of Quantification (ULOQ) Lower Limit of Quantification (LLOQ) Limit of Detection Precision (Inter-assay) Precision (Intra-assay) Average Linearity
SARS-CoV-2 S1 Indirect 1000 – 3.4 U/mL 700 U/mL 5.5 U/mL 1.7 U/mL 10% 9% 107%
SARS-CoV-2 S2 Indirect   1000 – 3.4 U/mL 700 U/mL 5.5 U/mL 1.7 U/mL 12% 9% 104%

Product Overview

The Q-Plex SARS-CoV-2 Human IgG (4-Plex) ELISA tests for IgG antibodies to either the SARS-CoV-2 S1 protein or the SARS-CoV-2 S2 protein. Our validation studies identified measurable improvement in clinical performance when results from the S1 and S2 assays are considered together rather than single assays (see assay validation data below). Quansys recommends that a sample should only be considered positive for the presence of SARS-CoV-2 reactive IgGs when antibodies reactive to both S1 and S2 are detected.

Negative samples, collected prior to August 2019, and known positive samples collected from individuals who tested positive for COVID-19 on a molecular test at least 14 days prior to sample collection were used to determine clinical sensitivity and specificity.


The Q-Plex SARS-CoV-2 Human IgG (4-plex) is a qualitative chemiluminescent assay (ELISA) allowing concurrent measurement of human IgG antibodies to SARS-CoV-2 S1 and SARS-CoV-2 S2 proteins in serum and plasma samples.


The Q-Plex SARS-CoV-2 Human IgG (4-plex) has been authorized by FDA under a EUA for use by high complexity CLIA labs.


Sensitive, reproducible, and convenient 96-well format requiring low sample volumes


Requires the Q-View™ Imaging System for analysis

Kit Content

Each kit contains a 96-well plate, featuring the relevant biomarker panel in each well, and all reagents required to perform testing.

Reagents Include:

  • Detection Mix
  • Calibrators (High, Low, Negative)
  • Substrate
  • Sample Diluents
  • Streptavidin HRP
  • Wash Buffer


All Quansys Q-Plex™ Multiplex and Singleplex assays require the use of the Q-View™ software to read and interpret the test results. A fully-functional, free trial version of the software is available to download, install, and use to analyze your first kit(s). At the end of the trial period, a purchased license is required to continue the use of the Q-View software.

Q-Plex arrays are developed and optimized to work with Q-View imagers. Quansys does not guarantee the results obtained from other imagers and not all imagers are compatible with Quansys Q-Plex arrays.

Other Equipment Recommendations

Publication Library

Search our publication library for all the peer-reviewed journals and research products that have utilized Q-Plex™ technology here.

In-Kit Certificate of Analysis

Search and download Certificates of Analysis for your Quansys Biosciences kits here.

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Our Response to COVID-19

As new variants of SARS-CoV-2 arise, the global response must change and adapt. Tracking the infection and our immune response towards it becomes increasingly important. Learn more about our response to COVID-19.

Similar Kits Available

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Not Finding What You Need?

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Not seeing the biomarker or analyte you need? Customize your kit! The Q-Plex™ Custom Assays are fully quantitative ELISA-based Chemiluminescent assay kits allowing the concurrent measurement of up to 18 biomarkers or analytes.

Send in Your Samples

Choose up to 18 different biomarkers that will work best for your research. Send in your samples and let us run them for you. 

Contact a Representative

Have questions about the kit or interested in more information? Contact one of our representative to get all your questions answered. 

As researchers and problem solvers ourselves, we understand the value of sound data. We are proud to be a part of research that can better the world. We value the relationships, partnerships, and friendships that we have built with the people who trust and use our technology. We are committed to building these relationships. You can count on us to answer the phone and take time to thoroughly address questions or concerns about any of our products. In an industry that is reputed for grandiose claims, we trust that our quality standards and our customer service set us apart from the competition. If you’re happy with our products or if you think we can do something better, we hope you will let us know.