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Aachen, Germany

Groll J.,achen University
Methods in enzymology | Year: 2010

Poly(ethylene oxide) (PEO) is known as an excellent coating material to minimize nonspecific protein adsorption. For an examination of biomolecules attached to surfaces with sensitivities down to the single-molecule level, demands on the surface additionally comprise low-intrinsic fluorescence of the coating material and a possibility to immobilize biomolecules in their functional conformation. One strategy that combines the protein-resistant properties of PEO with chemical functionality is the use of star-shaped PEOs that allow for interpolymer cross-linking. Our system consists of six-arm PEO-based star polymers functionalized with reactive isocyanate groups at the ends of the polymer chain. The isocyante groups allow intermolecular cross-linking so that high grafting densities may be achieved, which render the surfaces extremely resistant to protein adsorption. Application by spin coating offers a simple procedure for the preparation of minimally interacting surfaces. The reactive end groups may be further biofunctionalized to recognize specific biomolecules such as streptavidin or His-tagged proteins in specific geometries or as single isolated molecules. These properties, together with the advantageous chemical properties of PEO, render the surfaces ideal for immobilizing proteins with detection limits down to the single molecule level. This chapter focuses on the preparation of substrates that are suitable for single-molecule experiments. Besides a detailed description of surface preparation, two examples for the single-molecule detection of immobilized proteins, nucleosomes and RNase H, are presented that demonstrate the advantages of the star-polymer derived coatings over linear-grafted PEO. Copyright 2010 Elsevier Inc. All rights reserved. Source

Diessel D.,achen University | Hirtz M.,achen University | Otto N.,achen University | Robens N.,achen University | And 3 more authors.
Olhydraulik und Pneumatik | Year: 2013

A continuous improvement in the overall economic situation compared to previous years could also be felt in this year's leading trade fair MDA - Motion, Drive and Automation. In Hanover, numerous fluid power companies presented their latest innovations in hydraulics and pneumatics. The authors of the article draw a conclusion of personal highlights of the fair based on several selected examples. Source

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