omation mbers - Society for Laboratory Automation and Screening

WP036
Jeff Olson
Abbott Laboratories
R46S
200 Abbott Park Road
Abbott Park, Illinois 60064-6212
jeff.olson@abbott.com
Membrane-Bound Protein Crystallization Workstation
209
Co-Author(s)
Mark Chiu
Mike McCoy
Jeff Pan
This poster describes a recently developed method for dispensing protein-containing, gel-like, lipidic cubic phases
onto crystallization trays, and preparation of these trays for various protein crystallization experiments. Tiny
volumes (typically 200 nL – 1 µL) of lipidic cubic phase material containing either soluble or membrane associated
proteins are deposited onto multi-well trays for crystallization experiments which are prepared using either free
interface diffusion, sitting drop, or batch methodologies. The fundamental principle involves: (1) the preparation of
the protein containing gel and loading into a novel, gel dispensing device; (2) positive-displacement dispensing of
the protein containing gel onto the assay trays; (3) preparation of the trays for various experiments by automated
addition of precipitating buffers or other reagents, and (4) application of humidity control to reduce concentration
changes of the reagents due to evaporation. The system, which is based on a standard Gilson 215 pipetting
robot, is fully automated and enables a far greater number of membrane-protein crystallization experiments to be
performed than could be accomplished manually.
WP037
Cengiz S. Ozkan
University of California, Riverside
Mechanical Engineering
Bourns Hall, A305
Riverside, California 92521
cozkan@engr.ucr.edu
Cell Based Biosensors
Cell based biosensors offer the capability for detecting chemical and biological agents in a wide spectrum.
Membrane excitability in cells plays a key role in modulating the electrical activity due to chemical agents.
However, the complexity of these signals makes the interpretation of the cellular response to a chemical agent
rather difficult. It is possible to determine a frequency spectrum also known as the signature pattern vector
(SPV) for a given chemical agent through analysis of the power spectrum of the cell signal. It is also essential to
characterize single cell sensitivity and response time for specific chemical agents for developing detect-to-warn
biosensors. In order to determine the real time sensing capability of single cell based sensors, multi-chemical
or cascaded sensing is conducted and the performance of the sensor is evaluated. We describe a system for
the measurement of extracellular potentials from primary rat osteoblast cells isolated onto planar microelectrode
arrays using a gradient AC electric field. Fast Fourier and Wavelet Transformation techniques are used to extract
information related to the frequency of firing from the extracellular potential. Quantitative dose response curves
and response times are obtained using local time domain characterization techniques. Future applications of this
technique will also be discussed.
POSTER ABSTRACTS