Hi, this is Vanitha Margan, I’m a global Product Manager here at Bio-Rad Laboratories.
And today, I’ll be presenting information on Bio-Rad's new research use only Bio-Plex
SARS-CoV-2 Neutralization Antibody Assays.
In the ongoing effort to understand the SARS-CoV-2 that causes COVID-19, a key area of interest
for researchers particularly those working in vaccine development is understanding the
antibody response to arising variants by measuring SARS-COV-2 neutralizing antibodies.
This measurement allows researchers to compare the effectiveness of naturally acquired and
vaccine-induced antibody response.
These assays complement our existing Bio-Plex Pro IgA, IgG, and IgM 4-plex serology kits
for COVID-19 related research in vaccine development and post-market surveillance studies.
In today’s presentation, I’ll be covering the role of SARS-CoV-2 neutralizing antibodies
and introducing the Bio-Plex Pro SARS-CoV-2 Variant Neutralization Antibody assays available
from Bio-Rad.
I’ll also explain how these assays work, describe all the flexible assay options, and
highlight the benefits you’ll gain by using these assays.
Neutralizing antibodies to SARS-CoV-2 block virus entry into cell's Angiotensin Converting
Enzyme 2 or ACE2 receptors by binding to part of the virus’s spike protein.
When the virus’s spike’s entry is blocked, infection is prevented.
The Spike protein subunits, Spike 1 or S1 and Receptor Binding Domain or RBD, are prime
targets for neutralizing antibodies because of their role in viral entry into host cells
through the ACE2 receptor.
Mutations in these regions can potentially result in SARS-CoV-2 variants that are more
infectious with increased transmissibility or reduce the effectiveness of current vaccines.
Let’s now look at the Bio-Plex Pro SARS-CoV-2 Neutralization Antibody Assays.
These neutralization antibody assays quantitatively and qualitatively measure SARS-CoV-2 neutralizing
antibodies against two wild types and 11 variants of RBD and S1 protein subunits in less than
3 hours.
There are customizable options that provide the flexibility to mix and match your variants
of interest.
Additionally, the custom assay developer kit is available for novel variant assay development.
The kit includes everything you need to develop an assay using your own variant antigens.
These neutralization antibody assays are compatible with Research Use Only Bio-Rad platforms,
including the Bio-Plex 200 and Bio-Plex 3D Systems, as well as all other Research Use
Only xMAP platforms.
Let’s review how the assays work.
These assays are competitive multiplex immunofluorescence assays that differ from typical Bio-Plex sandwich
assays.
The SARS-CoV-2 antigen is coated on the bead.
The Biotinylated Detection ACE2 Receptor is added directly to the wells without washing.
The neutralizing antibodies compete with the ACE2 receptor to bind to the viral antigen
on the bead.
The amount of neutralizing antibodies that bind to viral antigens on the bead depends
on their specificity and affinity.
The final detection complex is formed with the addition of streptavidin phycoerythrin
conjugate.
Phycoerythrin serves as a fluorescent indicator.
It is the bound biotinylated detection ACE2 receptor interacting with streptavidin-phycoerythrin
that results in an output of Median Fluorescence Intensity or MFI signal.
The more effective the Neutralizing antibodies are at binding to the viral antigen in competition
with the ACE2 receptor, the lower the MFI signal will be.
Therefore, the inverse is observed from what we see with typical sandwich immunoassays.
For the results, percent inhibition is calculated by comparing sample MFI values to the negative
control.
The formula is available in the instruction manual for your reference.
Now I’m going to describe the flexible options these assays offer.
The 11-Plex Panel is a complete ready-to- use 96-well kit containing premixed magnetic
capture beads, a detection ACE2 receptor, a standard, a positive control, and buffers.
The kit measures the neutralizing antibodies against two wild-type and 9 variant antigens
of RBD and S1 protein subunits.
The 2-plex Panel contains RBD and S1 wild-type antigens in a complete ready-to-use 96-well
kit that can be mixed with any combination of variant antigen coupled beads without any
additional reagents. If you would like to mix and match any other combination of coupled
beads, Bio-Rad offers coupled beads for 9 variant antigens sold individually and Delta
RBD and Spike Trimer that is sold as 2-plex coupled beads. For a complete 96-well plate
customized kit, you can purchase the Neutralization Antibody standard, Biotinylated ACE2 Receptor,
and the Neutralization Antibody reagent kit.
All you have to provide is your own Positive control.
With new SARS-CoV-2 variants of interest and concern arising, such as the new Omicron variant,
the Bio-Plex SAR-CoV-2 Custom Assay Developer Kit enables development of novel variant neutralizing
antibody assays.
The assay developer kit includes tools you need to develop a new variant custom neutralizing
antibody assay.
It comes with SARS-COV-2 Neutralization Antibody 2-Plex Panel, plus an Amine Coupling Kit for
coupling proteins to magnetic beads, Magnetic carboxylated Bead region 27, and Bio-Plex
Serology Bead Storage Buffer.
All you need to provide are the new variant antigen of interest, the coupling reagents
EDAC, and Sulfo-NHS reagents. Here are the benefits that you can gain by using the Bio-Plex
Here are the benefits that you can gain by using the Bio-Plex
SARS-CoV-2 Neutralization Antibody Assays
The short and easy assay protocol enables you to run large sample sets
and produce results in less than three hours, saving you precious time.
The multiplex format allows you to measure neutralizing antibody responses specific to
SARS-CoV-2 wild-type and 9 variants simultaneously in a single well giving you a high throughput
method to increase your lab’s workflow efficiency.
With over 96% specificity, less than 10% intra-assay precision and less than 20% inter-assay precision,
you can be confident with the quality of results across a wide range of neutralizing antibody
responses over time.
You can find the performance data and find more information about these Bio-Plex Variant
Neutralization Antibody assays at bio-rad.com/NabMultiplex.
With that, thank you for attending today’s webinar.