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Full-Text Articles in Life Sciences
Comparison Of Two Separation Methods For Biological Particles: Field-Flow Fractionation (Fff) And Sucrose Density Gradients, Cody E. Garrison
Comparison Of Two Separation Methods For Biological Particles: Field-Flow Fractionation (Fff) And Sucrose Density Gradients, Cody E. Garrison
OES Theses and Dissertations
Sucrose gradient centrifugation and Field-flow fractionation (FFF) are two different particle separation methods that overcome the problems of similar size microorganisms clumping together during standard filtration methods. FFF separates particles based on size and density via the parabolic velocity profile of laminar flow in a ribbon-like channel. The sucrose method separates particles via centrifugation in a density gradient. Both techniques worked well in separating eukaryotic from prokaryotic microbes, with the preferred method depending on the type and relative abundance of organisms to be separated. Minicells were separated from mother cells in transformed Escherichia coli cultures, heterotrophic flagellates (e.g., Diplonema papillatum …
Fecal Indicator Bacteria In Knitting Mill Creek With A Comparison Of Methods Used To Enumerate E. Coli, Manju Nagarajan
Fecal Indicator Bacteria In Knitting Mill Creek With A Comparison Of Methods Used To Enumerate E. Coli, Manju Nagarajan
OES Theses and Dissertations
This research seeks to evaluate the impact of an urban, multi-use neighborhood on the bacteriological quality of water in Knitting Mill Creek, a blind arm of the Lafayette River, a sub-estuary of the lower Chesapeake Bay. A principal objective was to determine the effects of rainfall, a surrogate for run-off, on water-column concentrations of fecal-indicator bacteria (FIB). I collected water samples weekly (September 2009-December 2010) and biweekly (January 2010-December 2011) at a storm-sewer outfall and a nearby marina and quantified their E. coli and enterococci concentrations using Colilert-18 and Enterolert, most-probable-number assays. In addition, I took monthly samples for these …