SPR measures the change in refractive index near a sensor surface as analyte molecules bind to an immobilised ligand. The instrument records a sensorgram of response units over time. Fitting the association and dissociation phases gives the association rate constant (kon, M-1 s-1), the dissociation rate constant (koff, s-1), and the equilibrium dissociation constant KD = koff/kon. KD reports binding affinity. The rate constants describe how quickly the complex forms and falls apart. This affinity value is distinct from in vivo half-life, which needs separate pharmacokinetic assessment.
Instruments & Consumables
Surface Plasmon Resonance (SPR) Instruments
Nicoya SPR instruments for label-free binding kinetics and affinity screening
Endpoint assays such as ELISA tell you whether two molecules bind, not how fast or how tightly. The Nicoya SPR portfolio gives you three routes into real-time, label-free binding analysis: semi-automated OpenSPR for accessible two-channel kinetic analysis, Revo for automated four- or eight-channel digital SPR, and Alto for high-throughput 16-channel screening. All three are benchtop systems that measure association and dissociation in real time without requiring a fluorescent or enzymatic label on the interacting partners, enabling affinity and kinetic analysis from sensorgram data.
OpenSPR uses localised SPR with a nano-structured sensor surface. It runs as a 2-channel instrument with manual injection that can be semi-automated with the OpenSPR-XT module. Revo is the automated four- or eight-channel digital SPR option, combining digital microfluidics with nanotechnology-based biosensors in a compact benchtop system, where a disposable cartridge gives the four-channel format the throughput of a 96-well plate, needs no fluidics maintenance, and accepts your crude samples. Alto is the first SPR system to combine digital microfluidics with the sensor surface. It runs sixteen channels, needs as little as 2 microlitres of your sample, and handles crude samples. Alto also automates serial dilutions and supports real-time data acquisition and analysis through the Nicosystem platform. For fully automated, unattended 24/7 workflows, Alto Automation Suite is available. Between them, the three systems cover most of the throughput range you are likely to need.
Sensor and capture chemistry decide what you can measure: carboxyl sensors for amine coupling, NTA or anti-His for His-tagged capture, streptavidin for biotinylated targets, and Protein A for antibody-Fc capture. These systems give you label-free binding kinetics analysis at a capital cost well below the established core-facility platforms, so the work can stay in your own lab. That is why OpenSPR, Revo and Alto appear on benches like yours, running antibody characterisation, fragment and affinity screening, quantitation, and epitope mapping.
Matching the instrument and sensor to your experiment
1) Routine lower-throughput kinetics. Choose the two-channel OpenSPR for accessible, benchtop LSPR analysis of binding kinetics and affinity. For automated sample handling and higher screening capacity, OpenSPR-XT adds autosampler-based workflows using two 96-well plates and supports unattended runs of up to 24 hours.
2) Automated mid-throughput kinetics. Choose Revo when you need automated four- or eight-channel digital SPR, low sample consumption and disposable cartridges for up to 18 or 36 interactions per assay. It uses 2 microlitre sample volumes, supports automated serial dilutions, and is compatible with crude samples.
3) High-throughput screening. Choose Alto for 16-channel affinity screening, quantitation and epitope binning. Its cartridge workflow automates serial dilutions and measures up to 72 interactions per experiment. For fully automated, unattended 24/7 workflows, Alto Automation Suite is available.
4) Capture chemistry. Match the capture chemistry to your target: use NTA or anti-His chemistry for His-tagged ligands, streptavidin for biotinylated ligands, Protein A capture for compatible IgG or Fc-tagged ligands and carboxyl surfaces for covalent amine coupling for ligands without a suitable affinity tag.
5) Sensitivity and loading. High-sensitivity carboxyl SPR sensor chips suit small analytes or low concentrations, and high-capacity sensors suit larger immobilisation loads for you.
6) Reusable versus disposable formats: OpenSPR uses sensor surfaces that may be regenerated where assay conditions allow. Revo and Alto use disposable cartridges, removing the need for fluidics maintenance and sensor regeneration.
7) Analysis and workflow configuration. TraceDrawer software supports kinetic fitting for OpenSPR. Revo and Alto use the Nicosystem platform for experiment setup, data acquisition and analysis. The Essentials configuration provides kinetic and affinity analysis, while Pro configurations add application-specific functionality such as quantitation and screening. Alto can additionally be configured with epitope-binning and GxP modules.
All SPR instruments, sensor chips, cartridges and kits here come to you supplied by Nicoya.
Applications
Antibody discovery and affinity ranking
SPR confirms antibody clone binding to target antigen and ranks your clones by KD, reflecting binding affinity.
Small-molecule and fragment-based drug discovery
SPR can support fragment and small-molecule studies when assay design and immobilisation strategy are appropriate, complementing cell-based functional assays by resolving binding kinetics and affinity. For challenging low-molecular-weight analytes, select a high-sensitivity sensor chemistry.
Protein interaction mapping
SPR maps domain-level contacts between interacting proteins and measures how point mutations alter binding affinity, supporting your structure-function studies.
Biosimilar comparability studies
SPR can generate comparative binding data to support biosimilar analytical characterisation, including target-binding, Fc-receptor or cross-reactivity studies.
Kinetic rate constant determination
Multi-cycle or single-cycle formats give you association (kon) and dissociation (koff) rate constants that endpoint assays like ELISA cannot report.
Epitope binning and mapping
Sequential binding experiments identify whether two antibodies compete for the same epitope, complementing epitope mapping for your antibody panels.
Frequently asked questions
ELISA reports endpoint signal at a fixed concentration. It is mainly used for detection and relative quantification. SPR measures real-time binding and produces kinetic rate constants. It requires no detection antibody or secondary label, which removes confounding effects of labels on binding. ELISA gives higher throughput and suits large screening panels. SPR provides deeper mechanistic data on selected candidates.
His-tagged proteins are captured via NTA or anti-His sensors. Amine coupling via carboxyl sensors gives covalent attachment for ligands without a convenient tag. Streptavidin sensors capture biotinylated ligands with high stability and low off-rate. Protein A capture chemistry, and Protein G chemistry (where available for the selected platform), can orient compatible antibodies through their Fc region and help preserve antigen-binding accessibility. This preserves antigen-binding activity and enables direct comparisons across IgG formats.
Product catalogs
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