Publications by authors named "Ozge Kaygusuz"

2 Publications

  • Page 1 of 1

Rapid fabrication of teflon apertures by controlled high voltage pulses for formation of free standing planar lipid bilayer membrane.

Biomed Microdevices 2021 Feb 27;23(1):12. Epub 2021 Feb 27.

Department of Biomedical Engineering, Ankara Yıldırım Beyazıt University, Ankara, Turkey.

Free standing artificial lipid bilayers are widely used in the study of biological pores. In these types of studies, the free standing planar lipid bilayer is formed over a micron-sized aperture consisting of either polymer such as Polytetrafluoroethylene (PTFE, Teflon) or glass. Teflon is chemically inert, has a low dielectric constant, and has a high electrical resistance which combined allow for obtaining low noise recordings. This study investigates the reproducible generation of micropores in the range of 50-100 microns in diameter in a Teflon film using a high energy discharge set-up. The discharger set-up consists of a microprocessor, a transformer, a voltage regulator, and is controlled by a computer. We compared two approaches for pore creation: single and multi-pulse methods. The results showed that the multi-pulse method produced narrower aperture size distributions and is more convenient for lipid bilayer formation, and thus would have a higher success rate than the single-pulse method. The bilayer stability experiments showed that the lipid bilayer lasts for more than 33 h. Finally, as a proof-of-concept, we show that the single and multi-channel electrophysiology experiments were successfully performed with the apertures created by using the mentioned discharger. In conclusion, the described discharger provides reproducible Teflon-pores in a cheap and easy-to-operate manner.
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http://dx.doi.org/10.1007/s10544-021-00553-4DOI Listing
February 2021

The role of oxidative stress genes and effect of pH on methylene blue sensitized photooxidation of Escherichia coli.

Acta Biol Hung 2016 Mar;67(1):85-98

Department of Molecular Biology and Genetics, Faculty of Arts and Science, Bilecik Şeyh Edebali University , Bilecik , Turkey.

In this study, the survival time of wild type E. coli W3110 and 11 mutants was analysed with a plate count method in methylene blue added or control groups under daylight fluoroscence illumination (4950 lux) at different pH values (5.0, 6.0, 7.0, and 8.0) in phosphate buffer. As a result, while the number of bacteria did not decrease under photooxidative stress at pH 5.0 and 6.0 during a 6-hour incubation, the wild type and all mutants decreased more than 2 log. at pH 8.0, and approximately one log. at pH 7.0. It was determined that a 2 log decrease in wild type E. coli takes 3.7 h according to t99 value at pH 8, these values were 2.39 h in the katE mutant, 2.64 h in the soxR mutant, 2.67 h in the oxyR mutant, 2.71 h in the sodB mutant, 3 h in the btuE mutant, 3.38 h in the zwf mutant and 3.40 h in the soxS mutant, respectively (p < 0.05). The roles of these genes were proved with complement tests. Finally, it is found that the effectiveness of photooxidative stress is in direct relation with pH, and the katE, soxR, oxyR, sodB, btuE, zwf, and soxS genes are important for the protection against this stress.
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http://dx.doi.org/10.1556/018.67.2016.1.7DOI Listing
March 2016