Forum 11/20/2008

“nanoPore Optical Interferometry-A New Tool Used in Studying the Role of ToE1 in Cellular Apoptosis”

John Ervin, PhD – Director of R&D and Engineering, Silicon Kinetics

new tool, used to study the role of ToE1 (Target of Egr1) in cellular apoptosis, will be presented. Combining optical interferometry and a three dimensional nanoporous biochip in a technique called nanopore optical interferometry (nPOI), allows protein interactions to be studied without labels. Biochips are formed by etching 80 nm wide, 1,500 nm deep parallel pores into the face of a silicon wafer. During measurement, a white light probe passes through these light transmitting pores and interacts with the length of a protein monolayer attached to the pore walls. This creates an interference pattern, detected by reflection, which tracks the binding signal in real time. By using a porous structure, the sensitivity of the technique is enhanced as compared to planar approaches by a factor of 5, while the use of white light interferometry as the probe allows for wide instrument configurability. To date the technique has been used to study a wide range or protein/protein, protein/peptide, and protein/DNA interactions in order to quantify the affinity and kinetics of these. Often, experiments are performed using a benzaldehyde coated chip which needs no activation and allows proteins to be attached through a single covalent point. The benzaldehyde chips, as well as the available amino coupling chips have negligible non-specific biomolecular binding even with sera samples.

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