Aktualności

Dziekan Wydziału Biologii Uniwersytetu w Białymstoku

Zaprasza na seminarium naukowe, na którym

dr Katerina Makarova

z Zakładu Chemii Organicznej i Fizycznej

Wydziału Farmaceutycznego

Warszawskiego Uniwersytetu Medycznego

przedstawi referat zatytułowany:

In vivo free radicals detection in zebrafish embryos with X band Electron Paramagnetic Resonance

4 czerwca 2024 r. (wtorek), godz. 13.45

Sala 2058

Abstract:  Electron Paramagnetic Resonance (EPR) spectroscopy is the only method that enables the direct detection of paramagnetic species such as radicals. So far, X-band EPR was seldomly used for in vivo studies as the small size of X-band resonator and high power used to detect EPR signals were unsuitable for living organisms. To allow an in vivo detection of free radicals in living zebrafish embryos and larvae we designed specially-shaped glass and quartz capillaries. They allow detection of a single line EPR spectrum corresponding to eumelanin free radicals. The signal is visible in pigmented zebrafish embryos, and absent in the albino line or fish in which pigmentation was blocked with phenylthiourea. Melanin has very diverse roles and functions in various organisms, yet in most species it gives coloration to skin or eyes, and protects from UV radiation. When oxidized, melanin forms radicals, which could be detected with EPR spectroscopy.  

Beside new openings for melanoma studies, using specially-shaped capillaries together with eSpect+, systems of standard X-band EPR spectrometers can have other in vivo applications. The EPR parameters could be used to calculate membrane order parameters and, thus, give direct information about fluidity/rigidity of the membrane. For this purpose, we studied several spin probes, which EPR signal parameters are dependent on the environment. As a proof of principles, we demonstrate that our solutions allow detection of changes in the membrane fluidity in genetically-modified or chemically treated fish. We present the results of membrane fluidity studies at the single fish resolution.