[19]

Acoustic Wave Sensor Network Analysis for the Real-time Study of Biological Interactions.  C. N. Jayarajah and M. Thompson, Dept. of Chemistry, University of Toronto, Canada

   Differential gene expression in response to variation in environmental stress factors, have been observed in space flight.  In order to better understand altered cell function in space, a comprehensive knowledge of gene transcription under variable gravity is necessary.  As well, stimulated drug (Actinomycin-D) production has been observed in space; optimal technology to monitor such drug production and relevant biophysical interaction is necessary.  Biotechnology involving such biophysical characterization, involve fluid dynamics, which in turn is also affected by variation in gravitational stress.  Since any real time data of biochemical interactions in space are affected by several variables, there is a need for multidimensional data retrieval.  The acoustic wave biosensor offers multidimensional data, composed of observation variables, which in turn respond to corresponding experimental variables.  In addition, we are able to monitor the binding of DNA to the drug molecule, Actinomycin-D, and to RNA polymerase in transcription initiation, sequentially in the same experiment, as this is a label free detection method.  A gold coated - piezoelectric quartz crystal is used as the sensing device, onto which DNA is immobilized.  The real time impedance data from the sensor in response to the binding of RNA polymerase or Actinomycin-D to DNA is fit to an equivalent circuit model using a network analysis method.  From the multidimensional data obtained from the network analysis, a few latent variables are extracted using principal components (PCs) analysis.  These PCs allow us to see how the different observation variables contribute to the data set.  Consequently, we are able to extract the dominant experimental variable(s) at each stage of the real-time data.  This multivariate experimental technique provides a potential solution to the need for technology to investigate gene expression and relevant biochemical interactions under variable gravitational conditions at the nanoscale. 

(Supported by NSERC, Canada)