RELEASE OF SEQUESTERED mRNA IS RESPONSIBLE FOR A MASSIVE, NON-TRANSCRIPTIONAL INCREASE IN mRNA AFTER OXIDATIVE STRESS IN S

An Automated, Pressure-Driven Sampling Device for Harvesting from Liquid Cultures for Genomic and Biochemical Analysis

Anthony D. Aragon¹, Gabriel A. Quinones¹, Chris Allen¹, Jason Thomas¹, Sushmita Roy², George S. Davidson³, Peter D. Wentzell⁴, Brian Millier⁴, Jason E. Jaetao¹, Angelina L. Rodriguez¹, and Margaret Werner-Washburne¹

¹Department of Biology, University of New Mexico, Albuquerque, NM 87131, ²Department of Computer Science, University of New Mexico, Albuquerque, NM 87131, ³Sandia National Laboratories, Albuquerque, NM 87185, ⁴Department of Chemistry, Dalhousie University, Halifax, NS B3H 4J3, Canada. Correspondence should be addressed to M.W.W. (maggieww@unm.edu).

Routine, sterile sampling of intact cells from liquid cultures, in volumes needed for biochemical and genomics analyses, and with time points ranging from seconds to minutes presents a significant challenge for systems biology. Here we describe a relatively simple, automated, pneumatic-sampling device for harvesting up to 30-ml of liquid, in replicate, with sampling intervals as short as 10 s. The simplicity and modularity of the sampler allows it to be coupled with a variety of harvesting methods, e.g. filtration, centrifugation, etc. This device was used to study an extremely rapid increase in transcript abundance, in yeast cells in stationary-phase cultures, in response to oxidative stress. Correlation between biological replicate time courses harvested with this device measured by microarrays was extremely high. The sampler reported here enables robust, real-time, integrated studies at time intervals within the range of many important biological processes.