On This Page
|Bio-Plex Questions Answered by Our Experts||More Expert Coffee Chat Webinar Topics||Related Products||Resources|
Our customers asked our Bio-Rad application scientists about how multiplex assays are being used on the front lines to understand patient immune response during infection. A lively discussion was held about sample preparation, system maintenance, targets, panels, data analysis, coronavirus research, and more. Watch the video of this session and read the questions and answers below.
Air Date: June 3, 2020
We had so many great questions asked by the audience. Watch the whole video, or quickly jump to a specific question:
- 00:10 Introduction
- 3:27 What are multiplex Immunoassays? And why are they helpful for vaccine research?
- 7:19 Can multiplex immunoassays be used to look at patients exposed to coronavirus?
- 10:28 What sort of adjuvants is being used for COVID-19 vaccines? Are new ones being developed? Can multiplex immunoassays be used to help test which adjuvant is best?
- 13:42 Regarding antibody specificity and the ability to bind to a specific target or its fragment, what are the differences between an ELISA and a multiplex assay?
- 16:24 What ways are vaccines evaluated to ensure they are safe and nontoxic?
- 20:22 Will we need to optimize the assay to run patients’ samples infected with COVID-19? What are your recommendations?
- 23:24 I use these assays in preclinical assays can I use them in clinical trials too?
- 25:00 What types of positive and negative controls are essential to obtain when developing an in-house MIA (microsphere-based immunoassay)?
- 27:09 Are multiplex immunoassays used in QC'ing of manufactured products? What is the benefit of ELISAs?
- 29:47 Can someone use the plate more than once, for example, divide the plate twice?
- 33:00 What type of samples do you recommend to run with Bio-Plex assays? Do you think that serum would be a good choice knowing that most of the assays start with nasal swabs?
- 34:25 One of the challenges in MIA for serology purpose is finding that sample high enough for all the Ab of interest. What is the highest multiplex assay for antibodies screening have you ever developed? How did you look for a reference standard curve sample? How did you test the cross-reactivity?
- 39:48 Do various antibody affinities (attached to beads) affect the overall outcome?
- 41:06 Can you describe the assay to test for various antibody isotypes after COVID disease. Antigen (spike protein) coated to bead, add patient sample, then add beads coated with antibody to detect various isotypes? Is this a kit?
- 43:25 How do I compare sample data collected across different days? What controls can I use?
- 47:21 Is throughput an issue? What about data management?
- 49:22 Could you elaborate a little on the choice of clonality of Ab for selection for capture and detection? What are the trade-offs of using a polyclonal ab for capture?
- 52:53 Has anyone used these assays in their vaccine development?
- 55:54 Closing
Bio-Plex Questions Answered by Our Experts
Audience questions and answers from our Bio-Rad application scientist and Bio-Plex specialists grouped by common topics.
Bio-Plex Multiplex Immunoassays
What are multiplex immunoassays? How are they helpful for vaccine research?
Video time index (minutes:seconds) 3:27
Multiplex immunoassays are built on magnetic beads with different ratios of two fluorescent dyes that have a capture antibody or antigen coupled on to them, and just like an ELISA, they can be qualitative or quantitative. Each bead region has a unique ratio of these dyes that provides a unique spectral address. The vendor or person developing the assays designates which target that bead is specific for (e.g., IL-6 or TNF-alpha), which allows for multiple proteins (up to 100 on the Bio-Plex 200 or 500 on the Bio-Plex 3D System) to be measured in one well.
The standard immunoassay formats apply (e.g., indirect, direct, or sandwich), and a reporter dye, phycoerytherin, is used to measure the amount of target antigen or antibody captured. The signal readout is fluorescent intensity. The instrument that reads the beads in a 96-well plate is similar to a flow cytometer, with a sample probe that picks up liquid from each well, flows each bead one at a time through a cuvette, where each bead is interrogated. A red laser excites the two dyes in the bead to classify the specific assay, and a green laser excites the reporter dye, providing a median fluorscence intensity value proportional to the amount of protein captured in the assay.
Multiplex immunoassays are helpful in vaccine research because they can be used for immune response profiling in biological fluids like serum and plasma. Bio-Rad has Bio-Plex Pro Cytokine and Phosphoprotein kits that are helpful in studying animal models like mouse and rat in the research and preclinical phases or humans in clinical trials to elucidate what the immune response is during pathogen infection and post-vaccination.
Using our assay developer kit or amine coupling kits, researchers can develop custom serology assays with pathogen-specific antigens, for example, to monitor the levels of antibodies produced by the host or patient against specific pathogen epitopes or levels of neutralizing antibodies, which would indicate an effective immune response has been mounted.
See our website to learn about multiplex immunoassays and their applications: Bio-Plex Multiplex Immunoassay System
Regarding antibody specificity and ability to bind to a specific target or its fragment, what are the differences between an ELISA and a multiplex assay?
Video time index (minutes:seconds) 13:42
The underlying principles of ELISA and Bio-Plex immunoassays are the same; however, in application, there are many advantages to the multiplexed, bead-based assay. You may in fact use the same antibodies to coat the beads as you might to coat the well of a 96-well plate. The main difference is that the reporter in ELISA is traditionally colorimetric, although it could be fluorometric or another method; regardless, you’ll use a plate reader to measure an indirect signal.
In the Bio-Plex system, the reader instrument is much more sophisticated, more like a flow cytometer than a spectrophotometer, allowing you to directly count the numbers of positive beads. The major advantage is that multiplex immunoassay panels enable you to quantitate many targets simultaneously all in the same assay well.
Another difference between ELISA and multiplexing is that you need to consider cross-reactivity in the multiplex assays. You need your antibodies to be very specific and know that they don't cross-react with each other or the targets. We do cross-reactivity studies to validate and verify all our Bio-Plex assays, but of course with ELISA singleplex you don't do that.
For example, we have a 48-plex panel, so that means that there are 48 different antibody pairs together in that one well, and we've tested the cross-reactivities between all of the possible combinations, so we know that they're highly specific. To ensure quality results with multiplex immunoassays, this demonstration of the absence of cross-reactivity is one of the criteria that is absolutely required. So the antibody specificity in Bio-Plex assays is held to a very high stringency compared to ELISA because we are actually testing for it and provide that information for all the different assays in our panels.
What types of positive and negative controls are essential to obtain when developing an in-house MIA (microsphere-based immunoassay)?
Video time index (minutes:seconds) 25:00
When designing your own assay, you will need to provide the antibodies, both capture antibodies and a detection antibody, and you’ll need an appropriate antigen, perhaps isolated from a sample, to create a standard curve. After you have the assay designed and tested for cross-reactivity and sensitivity, when you're actually running it, you’ll need to use controls, either in the form of purified antigen or biological samples with known high or low levels of the target antigen. The controls should be run regularly to both verify the assay and ensure comparable results from day-to-day using the same assay with different samples.
Regarding the sample matrix you're using, for example, a biological fluid, you want everything in the controls and across samples to be as comparable as possible. Also, the ranges in which you'd expect to see the levels of your specific analyte, you want to have controls close to that level, or use a biological sample if possible with known levels. In case your analyte is present at very low levels, another option for a positive control is to use the same matrix as the sample, or a very similar matrix, and spike it.
Are multiplex immunoassays used for QC in manufacturing? What are the benefits of Bio-Plex assays vs. ELISAs?
Video time index (minutes:seconds) 27:09
We have customers that use Bio-Plex multiplex immunoassays in manufacturing; one is among the largest vaccine manufacturers in the world. They use them in several different applications; one is immunogenicity, where they're quantitating total IgG to determine the potency of a vaccine. They use the Bio-Plex platform to create their own competitive inhibition assays to characterize the antigens they're using, and to determine the specificity of monoclonal antibodies, and also in purity testing.
The advantages of our multiplex immunoassays over ELISA include many benefits that have strong significance in manufacturing and bioprocessing. Multiplex assays offer significant reductions in time and labor for similar amounts of data obtained. For example, with a large screening panel, you could see a savings of three weeks using our multiplex assays instead of running multiple individual ELISAs.
Another advantage is conservation of limited samples; you can get more data from a small sample. When working with animal models in preclinical studies, sample volume may be critical. If you use ELISA, you may have to make compromises regarding which analytes to measure, whereas if you use a multiplex immunoassay, you're able to quantitate many different analytes in a very small volume. For example, our rat cytokine panel measures 23 different analytes in a single well, usually requiring less than 15 µl of cell lysate.
In data collection and analysis, another advantage is that running a series of assays all on the same plate, with the same buffers, the same day reduces any confounding variables that can contribute to differences that may not be due to the biology.
Can a Bio-Plex assay plate be used more than once? For example, subdivide the plate in half and use it twice?
Video time index (minutes:seconds) 29:22
Bio-Plex assays are designed for single use on a 96-well plate. Generally, it’s best to plan your experiments so as to use the full 96-well plate in one run. Typically, samples are run in duplicate and, on average, you can get about 78 samples per plate with controls, a blank, and a standard curve.
The plate is not the limiting factor; it's the assay reagents and components. The beads are formulated to a defined concentration upon final dilution and cannot be reused. We use the magnetic Luminex beads; our incubation and washing steps rely on magnetic separation using our semi-manual washer or an automated version.
Regarding the idea to reuse a filled plate on which you've only used a portion of the plate for some samples, and you want to save the other portion of the plate for later use on another set of samples, rather than trying to preserve the unused half for later use, it would be better to aliquot only the reagents needed for half a plate, then buy extra plates, so you can fill and run each half separately.
The standards are also perishable. We always recommend that they be freshly prepared before use. We do not recommend reconstituting the lyophilized standards, storing at 4 ºC, and using them over multiple days. If you are planning on doing this, a better practice would be to purchase another vial of standards and use that to run the second half-plate.
One of the challenges in MIA for serology purposes is finding the signal high enough for all the antibodies of interest. What is the highest number of multiplex assays for antibody screening you have developed? How did you look for a reference standard curve sample? How did you test the cross-reactivity?
Video time index (minutes:seconds) 34:25
The fundamentals of the Luminex xMap technology are such that, depending on the instrument you’re using, you can read up to either a 50-plex, a 100-plex, or a 500-plex assay, which is the theoretical upper limit of a uniformly coupled bead set comprising a Bio-Plex assay, or any Luminex immunoassay.
In practice, a 500-plex protein immunoassay is not very feasible due to the possibilities for cross-reactivity among all the components: 500 capture antibodies, 500 detection antibodies, and 500 antigens gives 1.25 million possible interactions. Thus, multiplex assays can suffer in terms of sensitivity or cross-reactivity at very high multiplexing levels.
As mentioned earlier (13:42), we perform rigorous validation of our Bio-Plex assays before release, including testing all our multiplex panels for cross-reactivity. Bio-Plex assays routinely go up to 20 or more targets; for example, our largest off-the-shelf panel for many years was a 27-plex human cytokine panel, but we've recently expanded it to a 48-plex panel. We feel this number is close to the practical upper limit for which you would want to design and validate a panel. It is possible to go to higher multiplex with more stringent cross-reactivity testing, and we can work with you on creating custom panels. We consider these large panels to be most useful in the discovery stage of a project, after which you would narrow the range of targets down to a smaller subset of antigens of interest to be included in a final assay.
Regarding serology tests, in Life Science Research Bio-Plex (RUO) product portfolio, we don't have many serology tests; we do have a 6-plex isotyping assay to measure different levels of isotypes, where you're actually capturing an antibody. In the clinical setting, using detection beads coated with specific antibodies to quantitate target protein levels in different patient samples, our Clinical Diagnostics group has the BioPlex 2200 platform (IVD instrument and assays) that are in this format, with panels up to 10-plex.
Regarding a standard curve, you would need to have an antibody coupled to the detection beads that you know recognizes the target antigen specifically, then titrate that down to determine a range of physiologically relevant levels. So if you want a quantitative assay, it depends on the available antibodies you could use to create a standard curve; however, many serology assays are semi-quantitative, with levels and thresholds.
In terms of cross-reactivity, you would need to test all of the different beads with the different antigens coated on them against each specific reference antibody in the bead sets to ensure that you're only getting signal for your specific target. You would do that individually and with the beads all mixed together to ensure that the detection levels correspond in both cases.
Do various antibody affinities (attached to beads) affect the overall outcome?
Video time index (minutes:seconds) 39:49
Antibody binding is fundamental to Bio-Plex assays, so the affinities that each of the antibodies have to the target analyte will determine your lower limits of quantitation, the dynamic range of the assay, and thus the effective working range or assay sensitivity. Thus, when designing custom assays, that's definitely something to look into and optimize if you have the opportunity to choose among several possible antibody candidates.
If you're fortunate enough to have a selection of good antibodies towards a given antigen, whether monoclonal or even polyclonals, it's good to test them in combinations when making custom assays with the bead coupling kits. Try coupling some to the detection beads while using others as your biotinylated secondary, and alternate this to determine which combination gives you the best dynamic range and sensitivity.
Could you elaborate a little on the clonality of antibody selection for capture and detection? What are the trade-offs of using a polyclonal anitbody for capture?
Video time index (minutes:seconds) 49:22
In our preconfigured Bio-Plex assays, we use monoclonal antibodies for capture to help ensure reproducibility across different assay panels and different lots. As a vendor, we have many considerations in building our assays. We want to provide the best assay format, the best signal, and a good working range. We'll use the antibodies that give us the response that we're looking for, but our major concern is reproducibility; we strive to provide our customers with very comparable data from our kits.
We are not against using polyclonals in immunoassays, but you might not get lot-to-lot reproducibility with polyclonals. For a sandwich immunoassay, if you have a choice between using the polyclonal for detection or for capture, you'd probably want to use a monoclonal for the capture and then use the polyclonal for detection. In developing your own assays, and you have multiple antibodies available, it's best to try them in different configurations to determine which gives you the best sensitivity. Having selected an antibody, another issue is consistency and access to that particular antibody over time. You can reduce the risk of variability by obtaining a supply of the same polyclonal antibody.
Visit our website to view our selection of monoclonal and polyclonal antibodies, antibody conjugates, validated antibodies, and custom antibodies: Bio-Rad-Antibodies.com
Bio-Plex Immunoassay System
How do I compare sample data collected across different days? What controls can I use?
Video time index (minutes:seconds) 43:25
As with any quantitative immunoassay, you need to create a standard curve. As with many tests, ELISA and multiplex assays, the usual controls are standard curves using the controls included with the assay or panel, a spiked protein control that you create from a relevant biological sample, or even a patient sample exhibiting what you're looking for can serve as a control. We provide standards for all our ready-to-use Bio-Plex immunoassays; for example, the standards set for a cytokine panel allows you to create a standard curve for each cytokine in that assay panel, defining a range in which you can accurately measure that analyte in the assay.
To control for variability, you would look at the performance of the standard curves across every run to make sure that they're comparable. You can visually overlay them in our software; you can examine the accuracy of your recoveries and look at CV percentages to make sure that everything is very comparable between plates. There's also an assay control that's included in many of our kits that enables you to check that it's always falling within the correct range.
The ideal case would be for users to develop their own biologically relevant control for a particular assay. For example, if you're studying a disease sample and a non-disease sample, look at the different ranges of the analyte of interest that is also most similar to the samples you'll be testing, and add that to the assay control as a check in the range in which you expect your samples to fall. Then you can analyze that day-to-day and observe the trend to make sure that it's always falling within a specific range that you're comfortable with in terms of variability.
We’ve found that in practice, running these assays day-to-day, we see very little variability over days. For example, a standard that may have a median fluorescent intensity of 40 or 50 one day will show the same general level; it's not going to be 500 the next day, so you can overlay the standard curve for multiple days within the software and verify at that level.
When using lyophilized standards provided by the manufacturer, use a dilution series prepared fresh daily from the lyophilized standards. Proteins stored in solution, even at 4 ºC, may not be in the same state as when freshly reconstituted. If you're planning on using one control throughout several runs and don’t want to reconstitute them every day, or are using your own protein controls, it would be better to dilute them to the desired concentrations and store them at –80 ºC, and then pull one aliquot out each day. You want to minimize the number of free-thaw cycles to ensure that protein degradation is not skewing your results.
Is throughput an issue? What about data management?
Video time index (minutes:seconds) 47:21
Sample throughput is not a major limitation in the Bio-Plex Immunoassay System, which can be scaled up in various ways and is amenable to automation. Multiplex immunoassays generate quite a lot of data, so we've developed our Bio-Plex software so that you can easily manage that data and quickly visualize and organize your data. Bio-Plex Manager software is used to control the instrument; it has automatic features for curve optimization, with settings that can identify outliers for you, so you just click a button to very quickly analyze all of your standard curves at one time.
You can also export data to Bio-Plex Data Pro, a database background software, without any fear of modifying your original data, you're able to add columns of characteristics to the data set. You can combine different plates, you can overlay standard curves, visualize by groups and heat maps. So we provide a lot of flexibility in our software for dealing with mass amounts of data quickly and easily.
Sample Preparation for Bio-Plex Assays
What type of samples do you recommend to run with Bio-Plex assays? Do you think that serum would be a good choice given that most of the COVID-19 assays start with nasal swabs?
Video time index (minutes:seconds) 33:00
Most Bio-Plex assays are validated on biological samples, usually serum or plasma for in vivo assays, generally cell culture supernatants for in vitro assays. Nasal swabs are thus not the ideal sample type. It may be possible to solubilize a swab and use the eluate; however, nasal swab tests are typically used for the real-time PCR, looking for viral DNA or RNA, as opposed to antigens found perhaps as a reaction to an infection, or other proteins. The particular aspect of a disease or metabolic process you're investigating will determine what type of sample and detection method provides the most biologically relevant assay.
What are your recommendations for sample/virus inactivation that will not diminish cytokine levels?
Our recommendations for inactivation of virus for use on the Bio-Plex system are citations that document using a 2% paraformaldehyde solution to fix the sandwich assay to insure that any infectious agents left behind will be inactivated.
For customers concerned about possible infectious agents left behind in each well they can add the 1-4% paraformaldehyde solution after the assay is complete, then read it. NOTE: 20 ml per liter paraformaldehyde is 2%.
References on fixing sandwich assay with paraformaldehyde solution:
- Beadlyte Stop Solution, Catalog # 43-001. One vial containing 2.5ml of solution: 0.2% (v/v) formaldehyde in PBS, pH 7.4.
- Oliver KG et al. Multiplexed Analysis of Human Cytokines by Use of the FlowMetrix System. Clinical Chemistry 1998 44(9) 2057–2060. DOI: /10.1093/clinchem/44.9.2057
After the incubations, samples were diluted to 150 uL with PBS containing 20 mL/L formaldehyde and analyzed on a standard Becton Dickinson FACScan equipped with a Luminex FlowMetrix System.
- Faucner S et al. Protein Bead Array for the Detection of HIV-1 Antibodies from Fresh Plasma and Dried-Blood-Spot Specimens. Clinical Chemistry 2004 50(7) 1250–1253. DOI: 10.1373/clinchem.2004.032995
The beads were resuspended in 20 mL/L paraformaldehyde in phosphate-buffered saline and analyzed directly from the filter-bottomed, 96-well plate with a Luminex-100 System equipped with the Luminex Data Collector software ver. 1.7.
Bio-Plex Clinical Applications
I use these assays in preclinical assays; can I use them in clinical trials too?
Video time index (minutes:seconds) 23:24
Yes; the Bio-Plex multiplex immunoassay system is completely flexible, and can very easily be scaled up in various ways. It's amenable to automation, so as you advance in your clinical trials and your sample sizes grow to the thousands, you can increase sample throughput accordingly. Researchers have reported processing up to 5,000 samples in some applications, for example, in studying the circadian clock system.
We also offer comparable panels for different species in many of our multiplex assays. For example, in immune response profiling, we have rat and mouse cytokine panels that are very comparable to our offerings for human cytokines, enabling you to assess very similar targets in both your animal model of choice and then your patients in clinical trials. This eliminates the need to revalidate a number of different markers and streamlines the translational work.
Can multiplex immunoassays be used to look at patients exposed to coronavirus?
Video time index (minutes:seconds) 7:19
A lot of the COVID-19 research surrounds immunogenicity and the immunoprofiling of infections. This kind of multiplex platform lends itself nicely to that kind of research, even just to learn the basics of cytokine reaction to the infection. As we understand more using the larger targets, we can then narrow down the focus to specific antigens or specific key players in the response. We can even break down different populations as a predictive measure or to classify higher risk or lower risk categories of patients.
We have a large immunoassay panel, the Bio-Plex 48-plex human cytokine panel, and there's already been a lot of work done on establishing the early response in SARS-CoV-2 infection. Given the speed of the discoveries being made today, the multiplex immunoassay format really helps to determine protein profiles for a large number of targets in a much faster way than you would if you were looking at them individually. It really compresses the amount of time spent measuring all of the different analytes. With the fast pace of research in COVID-19 vaccine development, the Bio-Plex panels are good tools to have in your toolkit.
There was a really interesting publication that came out early this year in Lancet where scientists were looking at cytokine response using the 48-plex panel in patients. They were trying to determine how cytokine profiles may predict if a patient needs to go to intensive care or not.
Huang C et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020 Feb 15;395(10223):497-506. DOI: 10.1016/S0140-6736(20)30183-5.
Will we need to optimize the assay to run patient samples infected with COVID-19? What are your recommendations?
Video time index (minutes:seconds) 20:22
There are reports of using Bio-Plex assays with COVID-19 patient samples. In general, standard laboratory precautions would apply in line with the biosafety level required when handling any other specimens with communicable viral diseases such as hepatitis or HIV.
One thing to consider is heat inactivation, and you should definitely work in a biosafety hood during sample preparation. If you're working with clinical samples or otherwise, although not in a clinical setting, but rather doing basic research, sometimes vendors will also do viral inactivation before they send samples to you, so you can have a SARS-CoV-2–positive sample that is safer to use.
The instrument sanitizing protocol is a running 10% bleach solution through it.
The main contact risk when dealing with infectious samples is probably in opening the freezer or making aliquots, pipetting or dilution before adding samples to a plate, but then once they're on the plate you do a series of washes either manually or using an automated washer. You can treat the waste coming from contaminated washer with 10% bleach, and then at the very tail end of the whole assay after reading the plate in the instrument, there is a waste line that goes into a bottle there that can be treated similarly.
Can you describe the assay to test for various antibody isotypes after COVID disease? Would it be antigen (spike protein) coated onto beads, add patient sample, then add beads coated with antibody to detect various isotypes? Is this available as a kit?
Video time index (minutes:seconds) 41:00
This question actually describes a lot of the steps in developing your own assays. Spike proteins can definitely be coated onto the beads, nucleocapsid proteins are another option. You would coat them with things that you know will elicit an antibody response in different patients.
You could start by putting each of these different antigens on a different bead region to determine which antigens the circulating antibodies will recognize. Then your detection antibodies would be the anti-isotype, either anti-IgG, anti-IgM, or anti-IgA. At this point, even in the multiplexing format, these would have to be separate assays because there's only one reporting laser on the Bio-Plex 200 reader.
Thus, you would only be able to quantify binding to the antigen coated on the bead but not necessarily distinguish three different anti-isotype antibodies. You could have a multiplex assay, for example, for multiple nucleocapsid IgG antibodies, and then other multiplex assays with IgA or IgM-specific kits. There are ELISAs to look at different subtypes, but they're not able to have different antigens, they’re limited to one antigen at a time.
There are currently no Luminex-based assays for COVID antibodies on the market, but we have developed a trio of multiplex assays for the three isotypes. These could be used to quantitate antibodies against SARS-CoV-2 nucleocapsid, receptor-binding domain, spike 1, and spike 2 viral proteins, singly or in combinations. We are in the process of validating these assays now. We anticipate launching these products mid-January, 2021.
Visit our website to learn more and register to be notified of product updates:
Bio-Plex Pro SARS-CoV-2 Serology Assays
What sort of adjuvants are used for COVID-19 vaccines? Are new ones being developed? Can multiplex immunoassays be used to help test which adjuvant is best?
Video time index (minutes:seconds) 10:28
Adjuvants are additions to vaccine formulations that elicit higher levels of immunogenicity, enabling the patient to develop a stable immune response, for example, higher populations of memory B cells, with an optimized dose that provides high immunity with low toxicity.
In COVID-19 research, GlaxoSmithKline (GSK) is providing over one billion doses of their AS03 adjuvant, originally developed for their A/H1N1 flu vaccine during the 2009 swine flu epidemic. The AS03 adjuvant is being tested with some of the SARS-CoV-2 vaccines currently in development, which should help to reduce the development time because they've already established the safety profile for this specific adjuvant system.
Quickly assessing the safety profile for vaccines is really going to push vaccine development through clinical trials a lot faster so that's really nice to see. There are publications where multiplex immunoassays specifically Bio-Plex have been used to study adjuvants and the effects on immunogenicity. Gardasil is an example of a vaccine for HPV where Bio-Plex has been used early on in the development pre-clinical phases looking at different formulations of their aluminum adjuvant and the response in rhesus macaques.
This study examined the effects of aluminum adjuvant in an HPV vaccine using Bio-Plex assays:
Ruiz W et al. Kinetics and isotype profile of antibody responses in rhesus macaques induced following vaccination with HPV 6, 11, 16 and 18 L1-virus-like particles formulated with or without Merck aluminum adjuvant J Immune Based Ther Vaccines 3, 2 (2005). PMCID: PMC1097753
What ways are vaccines evaluated to ensure they are safe and nontoxic?
Video time index (minutes:seconds) 16:42
Vaccine safety is ensured very similarly to other therapeutics, going through a regulated process of pre-clinical studies followed by multiple phases of clinical trials. Pre-clinical studies seek to establish that a vaccine injection formulation, including adjuvants, is essentially non-toxic and to determine an efficacious dose.
In characterizing a vaccine, multiple methods can be used to assay potency and purity; however, multiplex immunoassays are particularly valuable in determining safety and efficacy.
In pre-clinical studies, you may be testing a vaccine in different animal models, or a specific type of cell line, perhaps analyzing cytokines in cell culture supernatants to determine immune response. You may be trying to find the correct animal model to ensure that the cytokine profiles or any other observed effects translate well to human testing. In the US, Food & Drug Administration (FDA) outlines this process very well in terms of the types of testing, emphasizing toxicity both generally and in reproductive biology, mutagenicity, carcinogenicity, and other metrics for pharmacological safety.
In pre-clinical studies, you also outline a dosing regimen, a range of doses and time points to administer the vaccine, after which human trials can begin. The first phase of human testing involves a small number of participants (healthy volunteers), and here you seek to establish the basic safety of the vaccine in humans and also quantify vaccine dosing levels required to achieve the desired efficacy, a large and lasting immune response, without harming the patient.
In Phase I trial of their mRNA SARS-CoV-2 vaccine, Moderna reported that one of the patients had an adverse effect, experiencing fever and dizziness; however, this patient was in the group that got the largest dose, and the effects were mild, with recovery in a few days. So Phase I serves to exclude the possibility of any acute bad outcomes before moving on to larger groups of patients in Phases II and III.
As the trial phases advance, the groups get larger, enabling a statistical view of the immune response and how efficacious your vaccine is while continuing to monitor safety over a longer term. Safety monitoring extends to post-market surveillance, with a number of research institutions and a much larger patient population documenting any adverse events, enabling a study of the after-effects of vaccines well beyond the time of market launch.
Has anyone used these assays in their vaccine development?
Video time index (minutes:seconds) 52:53
Several recent publications have reported using our off-the-shelf Bio-Plex assays, for example, to quantitate cytokines and other targets in immune response profiling. Researches can also use the Bio-Plex platform to create custom assays by coupling their own antibodies and antigens to Luminex beads, for example, to create a new serology assay.
Both off-the-shelf and custom coupled beads have been used in vaccine development throughout the whole development process, from pre-clinical studies through clinical trials and after-market studies. Bio-Plex assays can be used in vaccine research to determine whether or not you're eliciting the intended immune response, either by directly quantitating neutralizing antibodies, as for example with the Gardasil HPV vaccine, or by using cytokine levels to monitor host immune response indirectly. We offer species-spefiic assays for the rat and mouse models often used in pre-clinical trials, and our human cytokine assays can be used in the clinical phases.
The following publications highlight some of the possibilities for Bio-Plex applications in vaccine studies:
- Takahashi Yet al. Immunological studies of cerebrospinal fluid from patients with CNS symptoms after human papillomavirus vaccination. J Neuroimmunol. 2016;298:71–78. PMID: 27609278
- Smith JF et al. Evolution of type-specific immunoassays to evaluate the functional immune response to GARDASIL, a vaccine for Human Papillomavirus types 16, 18, 6, and 11. Hum Vaccin. 2008;4(2):134–142. DOI: 10.4161/hv.4.2.5261
- Nygard M et al. Evaluation of the long-term anti-human papillomavirus 6 (HPV6), 11, 16, and 18 immune responses generated by the quadrivalent HPV vaccine. Clin Vaccine Immunol. 2015;22(8):943–948 PMCID: PMC4519713
Bi-Weekly Webinar Series – Every other Wednesday at 9:00 AM PDT (17:00 BST)
Join our Application Scientists for an informal chat about the most relevant issues for
our customers, answers to Tech Support questions, new products, tips for success
in your work, and live Q&A.
Video time index (minutes:seconds) 28:18
Simultaneously quantify up to 500 proteins targets in a single 12.5 µl sample. Available as ready-to-use premixed multiplex panels and singleplex sets or in custom-mixed panels.
Multiple solutions to study host response to coronavirus infection, including assays to profile cytokine levels, immune and inflammation markers, and flow cytometry to monitor cellular immune response.
Bio-Plex Readers and Tools include the Bio-Plex 200 and Bio-Plex 3D Systems, Bio-Plex Pro Wash Station, and maintenance, calibration, verification, and validation kits.
Bio-Plex Manager and Bio-Plex Data Pro Software make it simple to run instruments using xMAP technology and analyze multiplex immunoassay data.
Bio-Plex System Applications and Uses
Watch short videos to learn how the Bio-Plex system works, how it is used in cardiovascular disease and leukemia research, biomarker identification, and citokinin expression in cancer.
Bench to Bedside
Learn how Bio-Plex assays and instruments are being used in cardiovascular disease and leukemia research.
Understanding Melanoma Biomarkers
Learn how the Bio-Plex system can help to identify early markers of melanoma in serum and blood samples from at-risk patients.
Learn how Bio-Plex assays and instruments are being used to monitor cytokine expression in cancer and in response to cancer vaccines.
Bio-Plex Quick Tip Videos
Bio-Plex Quick Tips
Planning for Assay Success Part 1
Bio-Plex Quick Tips
Planning for Assay Success Part 2
Bio-Plex Quick Tips
Planning for Assay Success Part 3
Bio-Plex Custom Assay Development Reagents
(PDF 67 KB)