Bio Layer Interferometry

Bio-Layer Interferometry

Bio Layer Interferometry uses optical interferometry as means of detection. The technology uses light waves to infer the thickness of bio layer(s) on the sensor.

Bio Layer Interferometry (BLI) works by shining a white light down the biosensor and a spectrometer which collects the light reflected back. Reflected light originates from the interface with the optical layer (a) and from the surface of the biocompatible layer (b) where it meets the surrounding solution. When light waves propagate back from the two reflecting surfaces they interact; some wavelengths show constructive interference, others destructive interference. This interference is captured by a spectrometer as a pattern of intensity variation by wavelength with a characteristic profile of peaks and troughs.
Because BLI only detects binding to the sensor surface, there is minimal interference from biological sample media. Proteins can be assayed in cell culture media or crude lysates without interference.

Pall ForteBio LogoThe Octet platform from Pall® ForteBio® are using Bio-Layer Interferometry (BLI) to detect binding of biomolecules label-free and in real time. Depending on the instrument they can read up to 96 sensors simultaneously. All Octet systems utilize proprietary single-use biosensors with an optical coating layer at the tip of each sensor. This optical surface is coated with a biocompatible matrix that can interact with molecules from a surrounding solution. The customer can buy pre-coated sensors or modify the sensor.
Furthermore, the BLItz® system is the perfect starter instrument for any lab. Designed just for small experiments, it’s manual, single-sample format allows label-free analysis right at the bench in 4 µl od sample. Apllications include testing column fractions for presence of protein of interest, checking protein activity before starting a complex experiment, characterizing proteins in cell lysates in their folded state or monitoring protein expression.

Feflected light
Reflected light