Tethered particle motion mediated by scattering from gold nanoparticles and darkfield microscopy

Structured illumination microscopy using extraordinary transmission through sub-wavelength hole-arrays

A new optical method for characterizing single molecule interactions based on dark field microscopy

Single-molecule techniques continue to gain in popularity in research disciplines such as the study of intermolecular interactions. These techniques provide information that otherwise would be lost by using bulk measurements that deal with a large number of molecules. We describe in this report the motion of tethered DNA molecules that have been...

Measuring the near-field of extra-ordinary transmission through a periodic hole-array

The knowledge of the near-field of extra-ordinary transmission through hole-arrays is mostly theoretical; there is less experimental validation of the theory. We study the near-field properties by measuring fluorescent molecules that are immersed in a solution and their Brownian motion. The measurements are performed by filling the space above...

Advances in the development of a novel method to be used in proteomics using gold nanobeads

The study of DNA-protein interactions is gaining increased attention due to their importance in cellular processes. Only a well-functioning interaction guaranties that such a process can take place without errors. So far, only a small percentage of these interactions have been unraveled, partially due to their complexity but also due to the fact...

Absolute fluorescence calibration

While fluorescence microscope systems remains an essential tool in modern biology and medical work, no compact instrumentation has been developed for the rapid calibration of such systems. Almost invariably results are presented in terms of the [AU], "arbitrary units". To remedy this situation we have developed a small, portable instrument - the...

Adaptation of nanoarrays for the study of ?-synuclein aggregation - preliminary results

In previous publications we have shown that we can perform enzymatic reactions in nanoarrays by means of a microarray-reader based on a conventional microscope. In this publication we report on a modification of this system in order to monitor the aggregation kinetics of the natively unfolded protein ?-synuclein. We describe the motivation for...

Three-dimensional analysis tool for segmenting and measuring the structure of telomeres in mammalian nuclei

Quantitative analysis in combination with fluorescence microscopy calls for innovative digital image measurement tools. We have developed a three-dimensional tool for segmenting and analyzing FISH stained telomeres in interphase nuclei. After deconvolution of the images, we segment the individual telomeres and measure a distribution parameter we...

A novel concept for a mid-field microscope

When light passes through a hole smaller than the wavelength of the light, the transmission is very low and the light is diffracted. This however changes if holes are arranged in a periodic array on metal. In that case the light couples to surface plasmons; this results in enhanced transmission, spectral selection and a small angular diffraction...

LEDs for fluorescence microscopy

Traditional light sources for fluorescence microscopy have been mercury lamps, xenon lamps, and lasers. These sources have been essential in the development of fluorescence microscopy but each can have serious disadvantages: lack of near monochromaticity, heat generation, cost, lifetime of the light source, and possible distortions due to...

Toward the development of a Three-Dimensional Mid–Field Microscope

Recently, an extraordinary transmission of light through small holes (<200 nm) in a thin metallic film has been described. This phenomenon has been shown to be the result of the photon-plasmon interaction in thin films where a periodic structure (such as a set of holes) is embedded in the film. One of the extraordinary results is that the beam...