Solid-state nanopores for probing DNA and protein

Solid-state nanopores are small nanometer-scale holes in thin membranes. When used to separate two chambers containing salt solution, any biomolecule passing from one chamber to the other is forced to pass through the pore constriction. An electric field applied across the membrane is used to create an ionic current and electrophoretically drive...

Single-molecule studies of the twisted, knotted, and broken genome

This thesis describes a series of single-molecule experiments aimed at understanding the physical properties of DNA itself and the proteins that interact with it. We developed and applied sensitive techniques that allowed us to directly probe the conformation and interactions of individual DNA molecules and proteins. Magnetic and optical...

Solid-state nanopores for scanning single molecules and mimicking biology

Solid-state nanopores, nanometer-size holes in a thin synthetic membrane, are a versatile tool for the detection and manipulation of charged biomolecules. This thesis describes mostly experimental work on DNA translocation through solid-state nanopores, which we study at the single-molecule level. In particular, we demonstrate length-wise ...

Statistical mechanics of protein solutions

We study theoretically thermodynamic properties of spherical globular proteins in aqueous solution with added monovalent salt. We show how one can determine an effective interaction potential between the proteins from experimental data as a function of salt concentration and we apply this to the protein lysozyme at a solution pH of 7.5 and ionic...

Bioseparations using surfactant-aided size-exclusion chromatography

In most bioprocesses one or more chromatographic steps are used in the purification of the product. Size-exclusion chromatography (SEC) is often one of these chromatographic steps. It is based on the difference in size and shape of the components to be separated and is used for the separation of molecules with a near identical chemical...