Accurate delivery of single biomolecules by polyethylene glycol coated submicrometer pipettes

Park CW, Knemeyer JP, Marme N, et al. Accurate delivery of single biomolecules by polyethylene glycol coated submicrometer pipettes. CHEMICAL PHYSICS. 2004;301(1):105-110.There is a great interest to quantitatively manipulate, separate, and deliver low concentrations or even single biomolecules in submicrometer-sized channels. We report the use of cross-linked four-star polyethylene glycol (PEG) as a new coating technique for microchannels. PEG-coating efficiently reduces the electroosmotic flow (EOF) and non-specific adsorption to the glass walls. Our results demonstrate that individual fluorescently labeled hydrophobic cell adhesion proteins (fibronectin molecules) can be drawn through PEG-coated submicrometer pipettes in aqueous solution by electrokinetic forces without the addition of detergents or other additives which potentially deteriorate the activity and specificity of biomolecules. (C) 2004 Elsevier B.V. All rights reserved