# Biolayer Interferometry (BLI) ## expand\_more [**CMI BLI resources and user guide**](/node/750966#bli-resources)**⬇︎** [Bio-Layer Interferometry (BLI)](https://www.sartorius.com/en/pr/octet) is an optical technique for measuring macromolecular interactions by analyzing interference patterns of white light reflected from the surface of a biosensor tip. BLI experiments are used to determine the kinetics and affinity of molecular interactions. In a BLI experiment, one molecule is immobilized to a [Dip and Read Biosensor](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection/biosensors-and-kits) and binding to a second molecule is measured. A change in the number of molecules bound to the end of the biosensor tip causes a shift in the interference pattern that is measured in real-time. Sensors are moved from one well of a microplate to another to change solution between samples (load sample and analyte sample) and buffer for baselines and dissocation. ![Biolayer Interferometry Diagram](/sites/g/files/omnuum4016/files/2025-01/BLI_diagram_design_1.jpg) The CMI has two Sartorius (formerly ForteBio) instruments for measuring BLI: the [Octet RED384 (now called Octet RH16)](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection/octet-label-free-detection-systems/octet-rh16) and the [BLItz (now called Octet N1)](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection/octet-label-free-detection-systems/octet-n1). The Octet RED384 is more sensitive and higher throughput and can be used for macromolecular and small molecule binding experiments. The BLItz uses a very small sample volume, but is more time consuming and cannot measure molecules smaller than 10 KDa. **Applications and General Features** ![BLI Instruments](/sites/g/files/omnuum4016/files/styles/hwp_1_1__360x360_scale/public/2025-01/BLI_wide.png?itok=MB8nRrHf) - Kinetic binding: ka, kd - Equilibrium binding: KD - Disposable biosensors (sensor regeneration not required) **Octet RED384 Features** - Simultaneous real-time binding on up to 16 biosensors - 96 or 384 well reagent plate format - Small molecule sensitivity **BLItz Feature** - Low sample volume: 4 μl sample Octet RED384 Resources BLItz Resources BLI Supplies ## Octet RED384 Resources [CMI OctetRED384 BLI Getting Started Guide](/sites/g/files/omnuum4016/files/2025-03/CMI%20OctetRED384%20BLI%20Getting%20Started%20Guide.pdf "CMI OctetRED384 BLI Getting Started Guide") [CMI OctetRED384 Guide to Epitope Binning](/sites/g/files/omnuum4016/files/cmi/files/cmi_octetred384_guide_to_epitope_binning.pdf "CMI OctetRED384 Guide to Epitope Binning") [Bio-Layer Interferometry (BLI) Technology](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection) from Sartorius (formerly ForteBio) [Purchase BLI Dip and Read sensors ](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection/biosensors-chips-kits)from Sartorius (formerly ForteBio) ## BLItz Resources [CMI BLItz Getting Started Guide](/sites/g/files/omnuum4016/files/2025-03/CMI%20BLItz%20Getting%20Started%20Guide.pdf "CMI BLItz Getting Started Guide") [BLItz User Guide](/sites/g/files/omnuum4016/files/cmi/files/blitz_user_guide.pdf "blitz_user_guide.pdf") from ForteBio [Bio-Layer Interferometry (BLI) Technology](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection) from Sartorius (formerly ForteBio) [Purchase BLI Dip and Read sensors ](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection/biosensors-chips-kits)from Sartorius (formerly ForteBio) ## BLI Supplies ## Octet RED 384 Supplies **User-Provided Required supplies:** - Sartorius (formerly ForteBio) Dip and Read sensors - Black 96-well plate to soak sensors - Black 96-well or 384-well plate for samples and reagents - Pipettors for sample handling **Optional provided supplies and equipement:** - Empty BLI Sensor trays to use as working tray during experiment - 8-sensor transfer tool - Refrigerated centrifuge with microplate rotor ## BLItz Supplies **User-Provide Required supplies:** - Sartorius (formerly ForteBio) Dip and Read sensors - 96-well plate to soak sensors **CMI-Provide Required Supplies:** - Black 0.5 ml tubes (provided by CMI) Sort**Popular Dip and Read Biosensors for Kinetics\*** **Sartorius Part Number** Streptavidin (SA) biosensors 18-5019 (96/tray) High Precision Streptavidin (SAX) biosensors 18-5117 Super-Streptavidin (SSA) biosensors (for small molecules) 18-5057 anti-His (HIS1K) biosensors 18-5120 Ni-NTA (NTA) biosensors 18-5101 Anti-Human IgG Fc biosensors 18-5010 \* See [Sartorius (formerly ForteBio) BLI website](https://www.sartorius.com/en/products/protein-analysis/octet-bli-detection/biosensors-and-kits) for more sensor types Sort**OCTET Black Microplates\*\*** **Part Number** Greiner Bio-One 96-well black flat-bottom PP, 200 µL 655209 (VWR 82050-784) Greiner Bio-One 384-well black flat-bottom PP, 80-120 µL 781209 (VWR 82051-318) Sartorius Octet 384TW microplates, black tilted-bottom PP, 60 µL 18-5166 \*\* Only Greiner Bio-One brand, black microplates or Sartorius (formerly ForteBio) plates are recommended by Sartorius for the Octet sample and reagent plate. [ Data Management and File Formats arrow\_circle\_right ](/data-management) See also:- [ molecular interactions ](/cmi-terms/molecular-interactions) - [ Biolayer Interferometry ](/cmi-terms/biolayer-interferometry)