By Emily Hubbell

Graduate student Yeliz Celik defended her doctoral thesis in November and will graduate with a doctoral degree in physics at the end of winter quarter. Her advisor is Dr. Braslavsky.

Celik’s thesis, “Experimental Investigation of the Interactions of Hyperactive Antifreeze Proteins with Ice Crystals,” reveals important findings about how antifreeze proteins (APFs) function.

AFPs are found in organisms that have to survive cold temperatures.The proteins protect these organisms by arresting the growth of ice crystals within their bodies.

The Braslavsky group was the first to use microfluidics in AFP research. With this technique, the researchers exchanged a solution around an ice crystal while maintaining fine temperature control, Celik said.

“We use these temperature-controlled microfluidic devices to study whether antifreeze proteins bind irreversibly or reversibly to ice surfaces,” she said.

The research revealed that antifreeze proteins bind irreversibly to the surface of an ice crystal. It also produced data demonstrating that AFPs can suppress ice melting.

Although the idea of superheating ice crystals in AFP solutions originated years ago, this was the first experiment to provide quantitative proof for the phenomenon.

Before joining the Braslavsky group in 2006, Celik earned her masters degree in science education from Bogazici University in Turkey. She plans to complete two years of post-doc research before teaching physics at the university level.

Celik says that having her work with AFPs published will be the most rewarding part of the research process.