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Research
A new imaging and micromanipulation tool for studying asymmetric cell division
A new single molecule technique will be developed, which combines the advantages of single particle tracking and magnetic tweezers. This new technique will enable the investigation of asymmetric cell division and cell polarity in vivo. Novel magneto-fluorescent nanoparticles will be used that allow for manipulation with magnetic gradients and simultaneous visualization of conjugated target molecules in living cells. Thus, it will be possible to generate intracellular activity gradient and (...)
Combination of double optical tweezers with highly sensitive fluorescence
For some fluorescence investigations it is feasible to allow for a controlled positioning of targets within the field of view. To this end, we built a modfied fluorescence set-up that additionally incorporates double optical tweezers. Briefly, in an optical tweezer, a transparent particle in the µm-range can be held by the radiation pressure of a tightly focussed beam of a high intensity infrared laser. By splitting the light into two beams which can be moved independently by a set of (...)
Single molecule observation of restriction enzyme interaction with DNA by fluorescence microscopy
Restriction enzymes display important tools in microbiology since they cut double stranded DNA at specific sequences 4-7 bp long. A remarkable, yet not fully understood feature is that they can find target sites among long, non-specific sequences at very high speed without consuming energy1,2. To explain this so-called "facilitated diffusion", two different mechanisms for enzyme translocation along the DNA have been proposed : "Sliding", in which the enzyme is bound non-specifically to the (...)
