Sartorius Biolayer Interferometry (Octet) Systems for Kinetics & Affinity

You’re looking for a faster, fluidics-free way to get trusted kinetics, affinity, and titer data—even from crude supernatants. Sartorius Octet® Bio-Layer Interferometry (BLI) systems combine real-time, label-free detection with “dip-and-read” disposable biosensors, letting you screen, quantify, and characterize proteins, antibodies, Fc/FcRn interactions, AAV capsids, and more—with minimal method development.

Sartorius Octet Biolayer Interferometry at a Glance

Octet BLI measures the wavelength shift that occurs when an analyte binds to a ligand on a fiber-optic sensor, producing real-time association and dissociation curves for ka, kd, and KD alongside rapid quantitation readouts. Because samples are brought to the sensor (no internal fluidics), you work directly in 96- or 384-well plates, reduce maintenance burden, and analyze complex matrices like culture supernatant or lysate with confidence.

At-a-glance benefits

• Real-time, label-free kinetics & affinity (ka, kd, KD)
• Fast titer quantitation from crude samples
• Fluidics-free, “dip-and-read” workflow

How Biolayer Interferometry (BLI) Works—and Why Octet Is Different

At the core is interference: light reflects from an internal reference and from the biosensor surface; binding increases optical thickness and shifts the interference pattern. Octet’s open, plate-based format moves sensors between wells, so you can parallelize assays without microfluidic channels—and avoid clogs, priming, or lengthy clean-in-place routines. It’s a practical contrast to flow-based SPR and a powerful complement when you need both techniques.

Why it matters to you

• Setup is fast; method development is flexible.
• Analyze both small molecules and large complexes.
• Use Octet as a standalone workhorse or as an orthogonal method with SPR.

BLI Applications: Kinetics, Titer, Epitope Binning & More

Octet BLI supports your pipeline from early discovery to process analytics without forcing a single assay format. You can profile binding kinetics and affinity in real time, quantify protein titer directly from crude supernatants, and resolve antibody relationships through epitope binning or off-rate ranking. The examples below highlight common, decision-ready use cases so you can map your study goals to the fastest workable assay.

• Kinetics & affinity: Determine ka, kd, KD for protein–protein, Fc/FcRn, and small-molecule interactions.
• Quantitation/titer: Rapid IgG/protein concentration using Protein A or tag-based capture; software templates accelerate setup.
• Epitope binning & off-rate ranking: 32×32 binning campaigns and full-plate off-rate ranking shorten clone triage.
• Viral vectors: Direct AAV capsid titer measurement with AAVX biosensors across upstream and downstream matrices.

What’s Included: Octet Instruments, Biosensors, Buffers & Software

The Octet ecosystem is designed to be complete out of the box: instruments for the throughput you need, “dip-and-read” biosensors that match your capture strategy, plates and buffers vetted for kinetics or quant, and analysis software to move from raw curves to reports. Use this section to pick the building blocks that align with your targets, sample types, and compliance requirements.

• Instruments: R-series benchtop (e.g., R8) for flexible day-to-day work; RH-series (RH16/RH96) for parallel sensing and automation.

• Biosensors: Ready-to-use chemistries—Protein A/G/L, Streptavidin (SA), Ni-NTA/Anti-His, AAVX—covering capture, kinetics, and quantitation.

• Reagents & plates: Sample Diluent 18-1104, Kinetics Buffer 18-1105, and low-volume 384-well plates support high-throughput runs.

• Software: Octet BLI Discovery (acquisition) and Octet Analysis Studio (multi-plate analysis, reporting, optional 21 CFR Part 11).

Why Choose Octet BLI: Fluidics-Free, Fast, Scalable

Octet replaces fragile flow paths with plate-based sensing, which cuts maintenance and shortens method development. You can run real-time kinetics and high-throughput titer on the same platform, even in complex matrices, then scale from pilot screens to binning campaigns without re-engineering your workflow. The points below summarize where BLI typically saves you the most time.

• Fluidics-free reliability with disposable sensors
• Scalable throughput from 8 channels to 96 sensors in parallel
• Works with crude samples (supernatants, lysates)
• Walk-away automation on RH-series with robust assay templates
• GxP-ready options with 21 CFR Part 11 software and IQ/OQ/PQ kits

Octet BLI Instruments — Models & Specifications

Choose your platform by throughput, assay mix, and data integrity needs. R-series systems are flexible for day-to-day kinetics and quantitation, while RH-series instruments add parallel sensing for full-plate screens and automation. The table summarizes channels, plate compatibility, and compliance options so you can shortlist a model before digging into detailed datasheets.

Octet Biosensors — Selection & Use Guidance

Biosensor chemistry determines how you capture analytes and what trade-offs you make between regeneration, sensitivity, and matrix tolerance. Start with the tag or domain you can rely on (Fc, His, biotin, capsid), then match it to a sensor optimized for kinetics or quantitation. Use the guide below to pick a starting sensor and confirm regeneration and buffer limits before routine use.

Decision Guide: Pick the Right Octet BLI Setup

Begin with your primary outcome—kinetics, titer, or binning—then adjust for sample complexity and daily plate counts. Lower-throughput method development is comfortable on R-series systems; high-density screens and off-rate ranking favor RH-series instruments. The quick rules that follow help you select channels and sensor chemistry without over-specifying the platform.

1. Goal first 

• Kinetics/affinity → R8 for flexible method dev; RH16 if plates/replicates grow; RH96 for large matrices and ranking.
• Titer/throughput → RH16/RH96 with Protein A or His-tag sensors.
• Binning → RH96 for 32×32 or larger campaigns.

2. Sample complexity 

• Crude supernatants/lysates favor BLI’s open format; choose buffers per sensor TN to control non-specific binding and avoid chelators for Ni-NTA.

3. Compliance

• For regulated environments, select GxP packages (21 CFR Part 11 software + IQ/OQ/PQ).

BLI vs SPR vs ELISA — When to Use Each

BLI, SPR, and ELISA answer related but different questions. BLI emphasizes speed and matrix tolerance with label-free, plate-based sensing; SPR offers chip-based flow precision for confirmatory kinetics; ELISA provides established endpoint quantitation at scale. Use the comparison table to place your study on the right method—and to decide when an orthogonal readout adds confidence.

Octet BLI FAQs

Q1. Protein A vs. Streptavidin sensors—how do I choose?
Use Protein A for IgG titer/rapid capture of Fc-containing antibodies; use SA when you already have a biotinylated ligand or need flexible immobilization for kinetics.

Q2. Can I analyze His-tag proteins directly?
Yes. Ni-NTA sensors enable direct quantitation and capture for kinetics—ensure buffers are free of EDTA/imidazole or similar chelators.

Q3. How fast is high-throughput binning on Octet?
On RH96, a 32×32 binning campaign can be completed in under eight hours, with full-plate off-rate ranking in minutes.

Q4. Do Octet systems support small-molecule kinetics?
Yes. The Octet R-series supports small-molecule characterization with appropriate assay design and buffer control.

Request a Quote or Talk to an Application Specialist

Tell us what you’re running (kinetics vs titer vs binning), expected throughput (samples/plate/day), sample type (supernatant, lysate, purified), and whether you need GxP. Contact Iright now and we’ll help you choose the right Octet instrument and biosensors, share method templates, and scope validation materials.