Biomolecular Interaction Analysis Service

Our biomolecular interaction analysis service is based on a Bio-Layer Interferometry (BLI) technology developed by ForteBio, capable of label-free detection and monitoring biomolecular interactions in real time. A huge array of biomolecular interactions can be studied, such as protein protein interactions, small molecule and protein interactions. With a strong expertise in protein science and years of experience offering flexible solutions to a world wide clientele, BiologicsCorp guarantees the delivery of very accurate analysis of your samples following work plans tailored to your specific needs.

Service Detection Range

BIC’s biomolecular interaction analysis service can measure wide range of biomolecular interactions including protein to protein, DNA to protein, metabolite to protein, antibody to antigen, enzyme to substrate/inhibitor, and small molecule to drug target interactions.

BLI Detection Range
BLI Network

Key Features

  • Label-free and Real-time Analysis: Monitor sample behavior with less limitations than traditional methods.
  • Crude Sample Compatibility: Insensitive to matrix pH or changes in refractive index and wide solvent tolerance.
  • Versatile Kinetic Analysis: Accurate kinetic analysis of large macromolecules such as IgG to small molecule fragments of 150 Da.
  • High Throughput: Up to 8 assays in parallel per 96-well plate.

Service Specifications

Service category Description Timeline Price
Sample preparation (optional)* 4-6 weeks
Antigen and antibody fragment characterization
  • Determination of ka, kd and KD for antibody-antigen binding
  • Affinity and off-rate ranking in crude supernatants
  • Antibody engineering and affinity maturation
Please inquire
Protein-protein/ peptide interactions
  • Structure/function and mechanism-of-action studies
  • Kinetic analysis of panels of structural variants
  • Wild-type versus mutant analysis
Protein-DNA/RNA interactions
  • Transcription factor interaction studies
  • RNA regulation by RNA binding proteins
  • Translational control mechanisms
Protein-lipid interactions
  • Protein-liposome interactions
  • Kinetic analysis of membrane proteins
Protein-small molecule interactions
  • Label-free detection down to 150 Da
  • Binding constants including ka, kd and KD
  • Rapid label-free library screening
Protein/antibody quantitation
  • Determination of the amount of protein/antibody present in your sample

*: We provide a one-stop biomolecular interaction analysis service starting from custom protein/ antibody production, allowing us to better assist our customers in preparing high quality samples suited for their intended application.

Samples and Shipping Requirements

  • It is best to ship your ligand/analyte pair (≥200μg for protein/antibody, ≥300μg for small molecule) after lyophilization to keep its activity.
  • Protein samples in solution should have a concentration larger than 0.5mg/ml with less than 20% glycerol. The storage buffer of liquid samples should not contain Tris and PBS buffer is recommended.

Bio-layer interferometry is a well-established optical label-free technique to study biomolecular interactions. In Octet® RED96 system, the interaction occurs at the very tip of a glass fiber-based BLI biosensor. White light passing through the glass fiber is reflected back from both the internal surface and the external interface (with the sample solution). As more molecules bind to the sensor, the thickness variation of the external layer of immobilized protein causes the interference pattern shifts. The pattern can be plotted as a nanometer shift of relative intensity vs. wavelength that can be recorded in real-time with high precision and accuracy.

As a promising biosensor platform, BLI meets the needs of fields as diverse as biological research, biotherapeutic and small molecule drug development research, immunogenicity studies and vaccine development, and QC.


BLI Publications

Verzijl D, Riedl T, Parren PW, Gerritsen AF. A Novel Label-free Cell-based Assay Technology Using Biolayer Interferometry. Biosens Bioelectron. 2016 Aug 28:87:388-395.

Sun Y, Xiao S, Chen J, Wang M, Zheng Z, Song S, Zhang L. Heat Shock Protein 90 Mediates the Apoptosis and Autophage in Nicotinic-Mycoepoxydiene-Treated HeLa Cells. Acta Biochim Biophys Sin (Shanghai). 2015 Jun: 47(6):451-8.

Shah NB, Duncan TM. Bio-layer Interferometry for Measuring Kinetics of Protein-protein Interactions and Allosteric Ligand Effects. J Vis Exp. 2014 Feb 18: (84):e51383.

A Case Study of Protein Protein Interaction Assay on Octet Platform

1.Programming the Instrument


  • A4-E4:Samples with different concentrations from high to low
  • F4: Negative control

2.Process Analysis


  1. Baseline: Baseline before immobilization to determine whether the combination curves are abnormal.
  2. Loading: After immobilized ligand is bonded to the biosensor, thickness of biosensor increases leading to rise of the curve.
  3. Baseline: Baseline after immobilization to guarantee that the curve is stable before association.
  4. Association: Analytes of multiple concentrations interact with the immobilized ligand, leading to increases of biosensor thickness and significant rise of the curve.
  5. Dissociation: During the dissociation process, the curve shows a decreasing trend.
  6. Elute sensor: Clean the biosensors and the measurement is finished.

3.Result Analysis

No. Conc.(nM) KD (M) KD Error kon(1/Ms) kon Error koff(1/s) Full R^2
A 100.0 <1.0E-12 2.42E-12 7.13E+06 1.07E+05 <1.0E-07 0.9657
B 33.3 <1.0E-12 2.42E-12 7.13E+06 1.07E+05 <1.0E-07 0.9657
C 10.0 <1.0E-12 2.42E-12 7.13E+06 1.07E+05 <1.0E-07 0.9657
D 3.3 <1.0E-12 2.42E-12 7.13E+06 1.07E+05 <1.0E-07 0.9657
E 1.0 <1.0E-12 2.42E-12 7.13E+06 1.07E+05 <1.0E-07 0.9657
  • Kon or Ka: Rate of association or "on-rate"
  • Koff or Kd: Rate of disassociation or "off-rate"
  • KD: Binding affinity constant


The immobilized ligand interacts strongly with the analyte in solution, as KD values of different concentrations are less than 1.0E-12.

Need more information? Please do not hesitate to get in touch.

Contact Us

phone+1 (317) 703-0614
fax +1 (855) 427-1516