Scanning of UV-VIS spectra of Sepharose beads trapped between two optical fibers allows real time Bioligand Interaction Assay (BIA) to be carried out on a surface that can be automatically renewed by BI technique.
Native proteins are monitored by UV spectrophotometry within 220 to 280 nm range. In addition, labeled biomolecules can be monitored either by VIS spectrophotometry or by fluorescence, allowing native and labeled species to be monitored simultaneously.
The BIA response curve comprises a leading edge, recorded during association of target biomolecules, with a specific bioligand attached to the bead surfaces, and a trailing edge, recorded when attached biomolecules are exposed to wash buffer. Weakly bound biomolecules will dissociate (solid line), while strongly bound remain attached (dotted line).