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Bio-Layer Interferometers

How Bio-Layer Interferometers Work & How We Save You Time & Money

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Bio-layer interferometry (BLI) diagram

Bio-layer interferometry, or BLI, is an optical analytical technique that observes the associative and dissociative interaction of molecules.

Biotech diagram

In chemistry, it is important to know the affinity, thermodynamic properties, and stoichiometry of a substance, or analyte. BLI provides this data by observing and measuring biomolecular interactions, particularly protein interactions, in vitro. It is an important tool in a wide variety of fields.

Using white light, BLI looks at how molecules bind to or disengage from other molecules. Because it is also a label-free technique, it does not use any isotopes that would chemically bind to and label proteins. These features make BLI highly useful for applications such as fragment screening, kinetic characterization, and real-time label-free chemical binding measurements. It is considered a strong alternative to Surface Plasmon Resonance (SPR), however, in comparison, it does have its advantages and disadvantages.

Bio-Layer Interferometer Applications, Benefits, & Costs

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In order to measure biomolecular interactions, BLI shines white light through a biosensor tip. In many cases, a Streptavidin (SA) biosensor is used. However, the biosensor tips available are customizable and vary in use based on the molecule being immobilized and characterized.

The sensor tip has two surfaces inside of it: an internal reference layer and a layer of immobilized proteins on the sensor tip. As the proteins interact with the sample, some molecules will bind to them. Molecular immobilization occurs through the utilization of the high affinity streptavidin-biotin interaction. The biological molecules—in this case, proteins—can be biotinylated using established protocols and immobilized onto the biosensor surface for assay development. In other words, biotin is attached to the protein in order to make detection of the protein possible. The high sensitivity and stable baseline of these biosensor tips supports both kinetic and quantitation experiments.

The more molecules—or ligands—that bind to the immobilized protein, the more interference will occur with the light as it interacts with it. The resulting reflected light’s wavelength will then be shifted. This shifted wavelength is then compared to the reference wavelength. The molecules that are bound or dissociating from the biosensor are the source of the interference pattern.

Other factors such as unbound molecules, changes in flow rate, and the refractive index of the surrounding medium do not have the same effect. Because of this, the resulting data from BLI can give great insight into a substance’s kinetics, quantitation, affinity, and molecular interactions.

Let’s look at some of the applications and benefits BLI offers.

Study of Kinetics

In chemistry, kinetics is the study of the rate that chemical processes occur. It is also called reaction kinetics. Real-time, label-free bio-layer interferometry is a useful tool used to observe these chemical processes. Specifically, binding affinity and rates lend themselves to this specific optical biosensing technique.

BLI’s ability to quickly measure association and dissociation rates, as well as equilibrium dissociation constants, without leaving behind label reagents makes it extremely valuable to the study of kinetics.

Vaccine Research

As populations grow and microbes evolve, fast and reliable vaccine research is becoming more and more important. BLI’s label-free and real-time testing capabilities make them fast and accurate tools for vaccine research. Areas of use for BLI within vaccine research are:

  • Epitome design, characterization, and recognition studies
  • Pathogen diversity and distribution
  • Antibody affinity and development
  • Host immune response characterization, diversity, and distribution studies
  • Nucleic acid and molecular pathogen-host interaction studies
  • Therapeutic and clinical studies

Furthermore, BLI has been used to characterize COVID-19 antibodies using specific capture reagents to immobilize the antibodies specific to the virus.

Analysis of Protein/Liposome Interactions

In drug discovery, development, and screening, knowing the interaction of relevant biomolecules and cell membranes is important. Artificial membrane systems, such as liposomes, are useful in determining these interactions due to their modularity. Their lipid composition, lipid ratio, and vesicle sizes can all be customized.

BLI offers a number of important benefits to studying these interactions. The high throughput samples, being label-free, can be reused with no risk of clogging that is present in other similar techniques.

For example, biosensor-based small molecule fragment screening with BLI is suitable for monitoring interactions between small molecules. This is due to the technology’s ability to distinguish between non-specific and non-ideal interactions. Examining binding profiles and responses leads to a reduced rate in false-positives.

Analysis of Protein/Protein Interactions

For understanding biological processes, protein-protein interaction observations are important. BLI is an accurate label-free optical tool that is being used to look at these interactions.

Although BLI is not affected by changes in the sample’s composition (unlike other methods), it is not as sensitive as those methods. This lack of change in the refractive index due to sample composition, alterations, its relative ease-of-use, and instrumentation flexibility make it a versatile tool for studying these types of interactions.

BLI Development

In 2005, ForteBio introduced its Octet® platform. The company, along with the Octet® platform, would later be acquired by Pall Corporation, then by Sartorius in April of 2020.

The platform was—and is—based on bio-layer interferometry (BLI) technology, and includes a whole set of systems including instruments, biosensors, reagents and assay kits used to support the evaluation of biomolecular interactions in 96- or 384-well microplates. Furthermore, it’s introduction has allowed for real-time, label-free analysis of chemical affinity, binding kinetics, and concentrations.

Since then, BLI has become a robust optical analytical tool that is used in a wide variety of fields. Of particular note are the advances made in the study of HIV-1. Since HIV-1’s discovery, our understanding of it has grown, however, a cure still remains elusive.

Recently, with the help of BLI, scientists have begun to look deeper at how the HIV-1 cells interact with specific envelopes in the body. If fully understood, these interactions could bring us one step closer to a cure that would help millions of people.

We Offer BLI Leases to Fit Every Need

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Founder-Friendly Leases

Our lease agreements are founder-friendly and flexible, helping you preserve working capital, strengthen the cash flow of your business, and keep business credit lines open for expansions, staffing, and other crucial operational expenses and business development opportunities.

2-5 Year Lease Lengths

Leases range from 2 to 5 years. Length will depend on several factors, including how long you want to use the equipment, equipment type, and your company’s financial position. These are standard factors leasing companies consider and help us tailor a lease agreement to fit your needs.

Your Choice of Manufacturer

We don’t carry an inventory. This means you’re not limited to a specific set of manufacturers. Instead, you can pick the equipment that aligns with your business goals and preferences. We’ll work with the manufacturer of your choice to get the equipment in your facility as quickly as possible.

Maintenance & Repair Coverage

Bundle preventive maintenance and repair coverage with your lease agreement. You can spread those payments over time. Easily maintain your equipment, minimize the chances something will break down, repair instrumentation quickly, and simplify your payment processes.

End-of-Lease Options

At the end of your lease, you have multiple options. You can either renew the lease at a significantly lower price, purchase the machine outright based on the fair market value of the original pricing, or call it a day and we’ll come the pick up the equipment for you free of charge.

No Loan-Like Terms

Our leases do not include loan-like terms, which can be restrictive or harmful in certain situations. We do not require debt covenants, IP pledges, collateral,  or equity participation. Our goal is to maximize your flexibility. When you lease with us, you’re collaborating with a true business partner.

In-House Underwriting Process

Our underwriting is done in-house. You can expect quicker turnaround, allowing you respond to your equipment needs as they arise. We require less documentation than traditional lenders and financiers and can get the equipment you need in operation more quickly.