535d Orientational Control of Immobilized Biomolecules on a Membrane Surface for Specific Protein Capture

Protein Capture Sufi Ahmed and Timothy Barbari Track-etched membranes, arranged in a stack, have recently found application in highthroughput analytical techniques for protein expression profiling. Examples include sampling blood serum for antibodies or other proteins that indicate disease and blotting tissue sections for specific biomarkers that may be unique to tumor cells. If maintaining sample morphology is important (as in tissue sections), track-etched membranes offer an additional advantage over conventional blotting membranes by minimizing image distortion due to lateral diffusion. The use of layered membranes produces replicates of each sample from a single transfer. Each membrane is then treated with a specific antibody for detection of a particular protein of interest. However, since proteins are depleted as they pass through the stack, a result of nonspecific binding, only a limited number of proteins can be analyzed and there is a loss in sensitivity. Because of these limitations, there is a need to develop membranes with enhanced specificity for a particular protein with minimal nonspecific binding. While traditional immobilization techniques, such as glutaraldehyde crosslinking, can result in a surface with some bioaffinity, they also cause severe losses in biological activity through denaturation, which in turn can significantly compromise sensitivity towards the target protein.