Zeiss inverted light microscope ______ ___ Agilent 5500 AFM with environmental chamber
Agilent 8500 FE-SEM
Research in Nanoscience
There are three separate research themes that I am working on in the Nanoscience Research Lab:
- High Pressure Biology
This work is part of an ongoing collaboration with Dr. Anurag Sharma under the Alfred P. Sloan Foundation grant from Carnegie Institution Washington.
Anurag Sharma has done pioneering work in the field by adapting the Diamond Anvil Cell to microbiological studies, and I am very excited to have him as a Visiting Research Scholar at the Nanoscience Research Lab.
In an article to appear soon in the Proceedings of the National Academy of Sciences, Anurag has shown how Escherichia coli can survive pressures as high as 12000 atmospheres.
E coli with dense ice (Ice-VI phase) crystals at 12000 atm.
In a more recent work (presented as a poster at the American Geophysical Union meeting in Dec. 2011) Anurag and I have successfully extracted the pressurized E Coli from the diamond anvil cell and studied them using electron and atomic force microscopy. Some of these images are shown below
SEM image of the extracted Escherichia coli cells after exposure to high pressures for several hours. These Escherichia coli cells show developed septa, as indication of cell growth at high-pressure. This observation is consistent with earlier study by Sharma et al. (2002 Science) demonstrating biological activity at high pressures.
AFM image of Escherichia coli cell with septa.
- Bacteriophage bound to a substrate
In this work I am studying bacteriophage M13 on a variety of substrates using SPM and optical microscopy techniques. This work has involved several undergraduate students: James Porter (class of 2009) Nick Hennigar (2009), Ben Anacleto (2010) and Nathaniel Steinsultz (2011). These students won the Sigma Pi Sigma undergraduate research award in 2008. Nathaniel Steinsultz won the Barry Goldwater Scholarship in 2010 and is currently a physics graduate student at the University of Maryland. An AFM image from our paper in the Nanotech Conference Proceedings was recently chosen as the image of the month on the Nanoscience and Technology Institute website.
- DNA Origami
This research project involves undergraduate students Lee Wizda and Yosuke Sugishita. We are designing DNA molecules that can self-assemble in certain desired configurations. In particular, I am interested in designing structures using the stacking interaction of DNA bases. This research involves two aspects of nanotechnology: (a) Computational design of a two and three-dimensional structure and simulation of its behavior; (b) Use of both optical and atomic force microscope to see if the programmed sequence of nucleotides assemble in a desired micron sized region with nanoscale precision. Lee and Yosuke have just won the Sigma Pi Sigma Undergraduate Research Award in 2012 for their work on this project.