Octet® SPRSensor Chips

1

SPR Sensor Chip Selection

Octet® SPR Sensor Chips

Sensor chip selection is a critical feature of every SPR
assay. From initial design and development, to dataacquisition and analysis; the overall data integrity isinfluenced by initial sensor chip selection. Therefore,
a number of different variables need to be taken into
account when choosing a sensor chip, including:

Octet® SPR sensor chips are comprised of a thin glass
slide coated with a semi-transparent gold film, protectedby a rigid plastic outer cassette to shield the gold surface
from direct handling (Figure 1). The gold surface of many
Octet® SPR sensor chips are coated with an additional
layer of carboxymethylated dextran which allows covalentmodification of the surface using a range of chemistries,
including amine and thiol. This allows the user to study
a wide variety of molecules such as proteins, antibodies,
nucleic acids and small molecules, in order to generate
kinetic, affinity, concentration and binding specificity data
in real-time.

 Assay Application
Whether kinetics, affinity or molecule screening are being
investigated Molecular Weight
Whether low, intermediate or high molecular weightligands or analytes are being analyzed
 Binding Capacity
The overall analyte mass which can be bound to thesensor chip due to the immobilized or captured ligand
The unique properties of each SPR sensor chip should
therefore be considered in the initial assay design in order
to align with the overall goals of the assay and to ensure
accurate and reproducible results.

Figure 1.
Typical Octet® SPR sensor chip in its protective cassette
2Octet® SPR Sensor ChipClassification
Octet® SPR sensor chips can be classified according to anumber of variables, such as their immobilization matrix(2D or 3D), their binding capacity (low, medium or high),or the type of bond formed with the ligand (covalent oraffinity capture).

2D - Planar Sensor Chips

3D - Planar Sensor Chips

2D - planar SPR sensor chips are characterized by acarboxylated but matrix-free surface, which facilitatesa low binding capacity. The lack of a matrix results in
the generation of a flat planar interface, which allows
interactions with large molecules, molecular complexes,
viruses or whole cells to take place closer to the sensor
surface, resulting in a higher interaction sensitivity. Suchsensor chips are predominantly used for work requiringa low ligand density to minimize any potential avidity
effects.

3D SPR sensor chips are generally modified witha carboxymethylated dextran matrix to allow theimmobilization of high densities of ligand to the sensor
chip surface, and can be individually classified according
to their level of binding capacity.
In general, the longer the dextran chains, the greater thebinding capacity, which makes 3D Octet® SPR sensor
chips especially useful in studying non-standard antibody
formats, and in the areas of small molecule and fragment
research.

Octet® SPR Sensor Chip

Applications

Octet® SPR SensorChip

Product
NumberCapacity

Octet® SPR
Maintenance Chip

19-0136

NoneOctet® SPR
COOH1 Sensor Chip

19-0053

LownnnOctet® SPR
CDL Sensor Chip

19-0127

Mediumnnn

Octet® SPR
CDH Sensor Chip

19-0128

HighnnnnOctet® SPR
PCH Sensor Chip19-0129

High+nOctet® SPR
HisCap Sensor Chip

19-0058

HighnOctet® SPR
SADH Sensor Chip

19-0130

Medium toHigh

Small
Molecules

Intermediate
Molecules

Large
Molecules

Kinetics

Affinity

Screening

LMW
Binding

nnnnnnInstrument Maintenancennnnnnnnnn

3Covalent
Coupling
Sensor Chips
Octet® SPR CDL Sensor
Chips
A thin, 3D low density carboxymethylated dextran
matrix allows a highly stable covalent bond with theligand to be generated. The short dextran chains
minimize the space between the surface and the target
molecule to improve sensitivity and reduce nonspecific binding (Figure 2).
Biocompatible with a wide variety of target molecules
such as whole cells, virus particles, large proteins andcomplexes, and carbohydrates.

Octet® SPR CDH Sensor
Chips
Suitable for almost all Octet® SPR assays, theOctet® SPR CDH sensor chip is comprised of a 3D
carboxymethylated dextran matrix sensor chip surface.
Molecules of interest can be covalently bound to thesurface using a range of different amine, aldehyde, thiolor carboxyl functional chemical groups.
The Octet® SPR CDH sensor chip is one of the mostwidely used Octet® SPR sensor chips due to its
versatility and high binding capacity, making it suitable
for many diverse applications from small fragment
research to large, complex molecular structures(Figure 3).

4Features and Benefits
Capacity and Surface
 Medium binding capacity
 Covalent coupling Matrix length from gold surface: 50 nm
 Short dextran matrix
 Minimal distance between analyte and planar surface
results in a highly sensitive interaction
Analytes and Ligands Intermediate (>1 kDa) to large (>25 kDa) molecules Can be used for whole cell or virus particle work
 Useful for protein-protein or large analytes
 Affinity ligands can be immobilized to create
additional capture chemistries

Features and Benefits
Capacity and Surface
 High binding capacity
 Produces a highly stable covalent bond
 Matrix length from gold surface: 150 nm
Analytes and Ligands
 Small molecules: fragments and organic compounds Large molecules, viruses and proteins Target interactions with low binding activity
 Biocompatible with a wide range of molecules pH: highly efficient capture over a wide range

Features and Benefits
Capacity and Surface
 Low binding capacity
 Covalent coupling Matrix length from gold surface: ~2 nm
 Minimal distance between analyte and planar surface
results in highly sensitive interactions
Analytes and Ligands
 Useful for large molecular weight analytes due to its
matrix-free surface
 Can be used for whole cell, virus particle, multivalentor large analyte assays
 Reduced avidity when using multivalent analytes
 Suitable for attaching molecular complexes orparticles
 Immobilize affinity ligands to create additional
capture chemistries

Features and Benefits
Capacity and Surface
 Highest capacity surface of all Octet® SPR sensorchips
 Matrix length from gold surface: 150 nm
Analytes and Ligands
 Useful for small molecules, such as fragments,organic molecules and low molecular weightcompounds
 Can be used in experimental conditions notfavourable to dextran polycarbonate surfaces pH: highly efficient capture over a wide range
 High signal to noise ratio facilitates optimal small
molecule screening

Octet® SPR COOH1 Sensor
Chips
The Octet® SPR COOH1 sensor chip is comprised ofa 2D planar, carboxylated oligoethylene oxide surface
which can be used to create a highly stable covalentbond between the sensor chip and desired ligand.
The lack of 3D matrix results in a low binding capacity
which allows interactions to take place closer to thesensor chip surface. The potential for non-specificbinding to positively charged analytes is decreased
due to the lack of a carboxymethylated dextran matrix.
These sensor chips can be also be used if interactions
are affected by the presence of either lectin or dextran.

Octet® SPR PCH Sensor
Chips
With similar properties to the Octet® SPR CDH sensor
chip, the Octet® SPR PCH sensor chip has a greater
degree of surface carboxylation and a denser matrix,
resulting in a significantly higher binding capacity.
Comprised of a non-dextran polycarboxylate hydrogel
surface, it provides an alternative to dextran-based
sensor chips.
This makes it ideal for small molecule, fragment and lowmolecular weight research, as well as experimentation
involving low analyte concentrations or unfavourable
immobilization conditions.

5Affinity CaptureSensor Chips
Octet® SPR Streptavidin
Sensor Chips
The interaction between streptavidin and biotin
results in a high affinity biomolecular interaction withnegligible dissociation of the ligand from the sensor
chip surface, making it an ideal choice for highcapacity, reproducible SPR experimentation.
The Octet® SPR SADH sensor chip consistsof streptavidin pre-immobilized on a 3D
carboxymethylated dextran hydrogel, which allows
binding to a variety of chemically or enzymaticallybiotinylated target ligands (Figure 4). Due to the highly
efficient binding between the immobilized streptavidin
and the biotin tagged ligand, only low nanomolar
concentrations of the ligand are usually required.

Octet® SPR HisCap Sensor
Chips
The Octet® SPR HisCap sensor chip consists of preimmobilized nitrilotriacetic acid (NTA) within a nondextran polysaccharide 3D surface, which can be used
for affinity capture coupling (Figure 5).
In comparison to the strong interaction between
streptavidin and biotin, the lower bond strength
observed between NTA and a His-tag allows theeasy removal of His-tagged ligand proteins and theregeneration of sensor chip surfaces using a variety ofconditions, including imidazole, SDS and EDTA.

6Features and Benefits
Capacity and Surface
 Medium to high binding capacity
 Senor chip surface has a lower electrostatic charge
compared to amine sensors
 Binding resistant to a wide range of conditions
including heat, pH and proteolysis
Analytes and Ligands
 Intermediate (>1 kDa) to large (>25 kDa) molecules Validated for a broad range of applications
 Controlled ligand orientation facilitates optimal
analyte capture with low interference of the targetligand pH: highly efficient capture over a wide range

Features and Benefits
Capacity and Surface
 High binding capacity
Analytes and Ligands Suitable alternative for proteins not amenable toamine coupling Small molecule, peptide or fragment kinetics
 Large molecule kinetic assays
 pH: highly efficient capture over a wide range
 Stable baseline for accurate kinetic analysis

12000
10000
Response (RU)

Figure 2
Octet® SPR CDL sensor chips are ideal for low capacity
reproducible immobilizations. Here, streptavidin wasimmobilized using amine coupling to approximately
500 RU.

8000
6000
4000
20000-2000
Time (s)
500

0500

1000

1500

20000

Response (RU)

Figure 3
Octet® SPR CDH sensor chips contain a high-capacity
carboxymethylated dextran matrix sensor chip surface,which allows higher immobilization levels. Here,
Carbonic Anhydrase II was immobilized to two different
densities of approximately 5000 and 7500 RU.

01600012000
8000
2000-2000
1500

200

Response (RU)

Figure 4Pre-immobilized streptavidin on the Octet® SPR
SADH sensor chip allows stable capture of biotinylatedmolecules. Here, biotinylated HER2 was captured atthree increasing densities.

Time (s)
1000

150
100
5000400

Time (s)
600

800

1000

1200

600
500
Response (RU)

Figure 5Octet® SPR HisCap sensor chips are ideal for stablecapture of his-tagged proteins. Minimal drift ensures
improved accuracy in data collection whilst retaining
the ability to easily regenerate the ligand molecule.

2004003002001000-100-200Time (s)
0500

600

700

8009007

Germany
Sartorius Lab Instruments
GmbH & Co. KG
Otto-Brenner-Strasse 2037079 Goettingen
Phone +49 551 308 0USASartorius Corporation
North America Inc.
565 Johnson Avenue
Bohemia, NY 11716
Toll-Free +1 800 368 7178

For further information, visit:www.sartorius.com/octet-support

Specifications subject to change without notice.
Copyright Sartorius Lab Instruments GmbH & Co. KG.
Version 4063_RevA 03 | 2022