ForteBio Octet QKe System

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The Octet QKe system performs label-free quantitation of antibodies, proteins, peptides, DNA and other biomolecules as well as kinetic characterization of biomolecular binding interactions. Like all Octet systems, the Octet QKe uses our simple Dip and Read assay format to place biosensors directly into 96-well microplates, eliminating the need for microfluidics. The QKe system is configured for eight-channel parallel analysis, enabling operators to increase throughput without increasing budget or headcount. Sample preparation workflow delays are eliminated as the system can analyze crude samples taken directly from bioreactors or periplasmic preparations without interference.

The Octet QKe system is a direct replacement for the Octet Q and Octet QK systems, and provides a higher performance spectrometer for faster data acquisition rates. This improvement results in greater sensitivity and wider dynamic range for quantitation and kinetic analysis over our earlier systems.

Key Features

  • Increased sensitivity and dynamic range for quantitation of proteins and peptides down to
    > 5 kDa
  • Excellent signal resolution for measuring protein and peptide kinetics
  • Re-racking of biosensors offers additional operational cost savings
  • Two acquisition speed options allow assay performance to be customized


System Octet QKe Octet RED96
Setting 0.3 Hz, 40 avg 0.6 Hz, 5 avg 5 Hz, 20 avg
kon (1/Ms) 1.37E+05 1.08E+05 1.03E+05
koff (1/s) 8.00E-02 7.25E-02 6.56E-02
kD (M) 5.82E-07 6.71E-07 6.39E-07
S/N @ [0.5 KD] 30.8 14.3 29.1

The standard acquisition rate of 0.6 Hz with 5 averages per data point (1 data point per 1.6 seconds) is the default setting on the Octet QKe and QK384 instruments. The high sensitivity acquisition rate of 0.3 Hz (1 data point per 3.3 seconds) allows the software to perform 40 averages per data point to reduce noise and enhance signal to noise ratios, and gives the Octet QKe system enhanced sensitivity for quantitation of proteins.

Kinetic analysis benefits for proteins and peptides with Octet QKe system enhancements:

  • Detection and analysis of lower molecular weight proteins and peptides
  • High resolution binding data allow monitoring of protein or peptide interactions at different concentrations for more reliable measurement of kinetic constants

Biosensor Re-racking

The Octet QKe system provides the ability to re-rack biosensors at the end of an experiment. Biosensor re-racking provides enhanced flexibility in loading ligands on biosensors and reduces operational costs when biosensors are loaded with precious target reagents. Combining lower costs with increased flexibility and superior data quality, the Octet QKesystem provides a value-added alternative to other label-free instruments for your assays.