Giuliano Zanchetta, featured ILCC liquid crystal artist, April 2009

Giuliano Zanchetta received his PhD in Physics in December 2007 from the University of Milano (advisor Tommaso Bellini) with a thesis on LC ordering of short DNA fragments, for which he was awarded the Glenn Brown Prize in 2008.

In 2008 he was a post-doctoral research associate at the University of Colorado at Boulder, in the Liquid Crystal Materials Research Center directed by Noel Clark, and he is currently a postdoc at the University of Milano, in the Complex Fluids and Molecular Biophysics Lab.

The picture reproduces the polarized microscopy texture of the columnar phase of small fragments of double-stranded DNA (12 nucleotides long self-complementary sequences: CGCGAATTCGCG). Aqueous solutions of short DNA helices were recently found to show chiral nematic and hexagonal columnar LC phases via the end-to-end adhesion and consequent stacking of the duplex oligomers into polydisperse anisotropic rod-shaped aggregates (M.Nakata et al. Science 318, 1276 (2007)).

The connection between DNA duplexing and LC formation suggests that LC ordering may be autocatalytic for the growth of longer complementary duplex DNA in mixtures in which both complementary and noncomplementary short DNA strands are present; such assembly could have been a mechanism for the prebiotic appearance of DNA-like molecules on primordial Earth.

The picture, 800 x 600 micrometers, was taken on a TE200 Nikon Microscope, with a Nikon DS-5M camera. The image was also selected for an Honorable Mention in Olympus Bioscapes Competition 2008.

Jury comment: an exquisite play of geometry and color captured with perfect technique yields a photo that really shows how beautiful liquid crystals can be. And knowing what material is behind the photo makes it all the more exciting.
His research focuses on the experimental investigation of complex fluids and self-assembly of biomolecules, in particular the liquid crystalline ordering and phase separation in DNA and RNA aqueous solutions, interactions between liquid crystals and biomolecules, aggregation phenomena in colloids, polymers and proteins.