Scientists at the Braunschweig University of Technology have developed tiny adapters that allow the coupling of molecules to nanostructures and their precise positioning on the scale of a millionth of a millimeter.
This development is of relevance especially for DNA sequencing, which is considered the key technology for the analysis of inherited diseases. The latest results are presented in the current issue of the journal “Nano Letters”.
Immobilization strategy: DNA origami (grey rectangles) equipped with a fluorescent dye (red) occupy the small holes in the metal film (ZMWs) in a way that only one adapter fits per cavity.
Comparison between optimal Poisson distribution and the experimentally measured distribution in ZMWs of 200 nm.
For DNA sequencing, individual nucleotides are analyzed which are the building blocks of DNA. “Monitoring the incorporation of single nucleotides into a full DNA strand in real-time is a revolutionary method”, Prof. Philip Tinnefeld explains. “It’s almost a live broadcast”.
Special proteins, the so-called DNA polymerases, incorporate the nucleotides in a zipper like fashion to build a double stranded DNA strand. In order to observe this process and extract the order of nucleotides, scientists employ special cover slides. A glass slide is coated with a thin metal film that contains tiny holes, so-called zeromode waveguides (ZMWs).
“The challenge for this application is to equip each of these nano-holes with exactly one polymerase that utilize the nucleotides”, Prof. Philip Tinnefeld says. Usually, these biomolecules are deposited randomly in the ZMWs, which results in many empty ZMWs while others contain multiple polymerase molecules. Even for the optimal situation, only 37 % of the holes can be used, as the expert for Nano-Bio-Sciences explains.
Coupling and positioning of molecules
His research group now achieved a more efficient usage of the ZMWs by developing a new binding strategy. For this, the nano-experts from the Institute for Physical and Theoretical Chemistry in the Laboratory of Emerging Nanometrology (Braunschweig University of Technology) could use their experience of working with the so-called DNA origami technique: the Braunschweig scientists literally fold precisely fitting structures from single viral DNA strands.
The nano-adapters were designed such that exactly one DNA origami can bind in every ZMW. The nano-adapters additionally provide docking points for functional units, like fluorescent dyes or the polymerase molecules that are used for DNA sequencing. “With our novel strategy, we connect single molecules via DNA origami with the lithographically fabricated ZMWs. This procedure can improve the efficiency of DNA sequencing and also be beneficial for applications in other areas of research like molecular electronics”, Prof. Tinnefeld summarizes.
About the project
This research project of the NanoBioSciences group of Prof. Philip Tinnfeld (Institute for Physical and Theoretical Chemistry) was conducted at the new Laboratory of Emerging Nanometrology of the Braunschweig University of Technology and was funded by a Starting Grant of the European Research Council (SiMBA).
E. Pibiri, P. Holzmeister, B. Lalkens, G.P. Acuna, P. Tinnefeld (2014):Single-Molecule Positioning in Zeromode Waveguides by DNA Origami Nano-Adapters - Nano Lett.
Prof. Philip Tinnefeld
Dr. Guillermo Acuna
Institut für Physikalische und Theoretische Chemie
Laboratory of Emerging Nanometrology
Technische Universität Braunschweig
Tel: 0531 391 5330
Stephan Nachtigall | idw - Informationsdienst Wissenschaft
New Analysis Technique for Chiral Activity in Molecules
30.11.2015 | Korea Advanced Institute of Science and Technology
Two decades of training students and experts in tracking infectious disease
27.11.2015 | Hochschule für Angewandte Wissenschaften Hamburg
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
30.11.2015 | Event News
25.11.2015 | Event News
17.11.2015 | Event News
30.11.2015 | Ecology, The Environment and Conservation
30.11.2015 | Event News
30.11.2015 | Power and Electrical Engineering