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Biomedical subjects

M Stuke

Publications and source records attributed to M Stuke.

7 recordsLinked to original sources
PubMed2001

Highly efficient single molecule detection in microstructures.

For DNA single molecule sequencing, the complete detection of all dye-labeled monomers which are cleaved off during the sequencing reaction is an essential requirement. In this work we address the feasibility of single molecule detection in microstructures with a confocal multi element set-up. We present statistical data on single molecule recognition and explain a refined data evaluation technique for single molecule burst analysis. From these data the signal-to-noise ratio in microstructures is evaluated as well as the overall detection efficiency. So far, detection efficiencies of single molecule events of up to 60% have been shown in microstructures.

Biochemistry↗
PubMed2001

Towards a general procedure for sequencing single DNA molecules.

In this paper we report on the latest technical advances towards single molecule sequencing, a useful method currently developed especially for fast and easy de novo sequencing. Different approaches for complete labeling of DNA with fluorescent dyes are described. In addition, the experimental set-up for the sequencing process is shown. We demonstrate the ability to purify the buffer and enzyme solutions. Inorganic buffers were purified down to at least 20 fM of remaining fluorescent impurities. The exonuclease buffer solution could be cleaned down to 0.8 pM whereby its full activity was kept. Finally, we show a selection procedure for beads and present the data of a model experiment, in which immobilized DNA is degraded by an exonuclease within a polymethylmethacrylate (PMMA) microstructure. Furthermore, the mathematical processing of the obtained raw data is described. A first complete experimental cycle is shown, combining all preparatory steps which are necessary for single molecule sequencing in microstructures.

Biochemistry↗
PubMed1997

Laser Rapid Prototyping of Photonic Band-Gap Microstructures

Three-dimensional periodic microstructures of aluminum oxide, which are important for creating photonic band-gap structures (PBGs), were fabricated by laser rapid prototyping by means of laser-induced direct-write deposition from the gas phase. The structures consisted of layers of parallel rods forming a face-centered tetragonal lattice with lattice constants of 66 and 133 micrometers. These structures showed transmission minima centered around 4 terahertz (75 micrometers) and 2 terahertz (150 micrometers), respectively. PBGs will allow precise control of the optical properties of materials, including lasers without threshold.

Journal Article↗
PubMed1989

Animal experiments for the determination of an optimal wavelength for retinal coagulations.

The retina of rabbits was coagulated with different wave-lengths (570-630 nm) using a tunable dye laser with Rhodamin 6G. To achieve comparable ophthalmoscopic appearance the intensity of the laser beam was varied with neutral filters of varying absorption. Histologic examination of fresh coagulation effects and 3-week-old coagulation scars showed no difference in relation to the wave-length used. Theoretically, 577 nm seems to be a particularly useful wavelength for the treatment of a wide variety of retinal lesions because it is not absorbed in xanthophyll and penetrates opacities of the optic media better than argon blue green. Furthermore, it is absorbed maximally in hemoglobin, making it particularly suitable for the coagulation of blood vessels.

Animals↗