Investigation of the role of anti-freeze glyco-proteins in the circulation system of Antarctic fish

A variety of biochemical techniques were used to isolate Anti-Freeze Glyco-Proteins (AFGPs) from Antarctic fish blood, which was then conjugated directly to a fluorescent marker. We synthesised silicon dioxide nanobeads incorporating a fluorescent probe and coupled these to AFGP via a multimeric linking protein or dendrimer based on G4.5 poly(amidoamine).

These modified nanobeads, consisting of a fluorescent particle surrounded by AFGPs, were designed to serve as a proxy for ice crystals that have bound AFGPs. When introduced into the circulation of the fish, we were able to follow the fate of free fluorescent AFGP and particle-bound fluorescent AFGP (the latter serving as a proxy for ice in the circulation). Frozen and alcohol-fixed tissues were returned to New Zealand for further laboratory analysis.