Join us for our seminar this Friday, December 10th, at 1:30 PM in ILC 118. Directly after the seminar, at 2:30 pm, we will be celebrating our graduating seniors with a wizard hat ceremony!
“An Exciting Way to Identify Sagebrush”
Aurora Zantman
L. Warner Lab, Boise State University
The sagebrush steppe (Artemisia spp.) has dramatically decreased in size, due to natural and anthropogenic disturbances such as fires, grazing, and urban development, raising concern for the animals that depend on it for food and shelter. Ecological restoration can increase the availability of sagebrush ecosystems when the proper vegetation is restored to areas impacted by natural and anthropological disturbances. However, in the case of sagebrush, identification can be challenging as morphological features among the subspecies are very similar.
Sagebrush has been found to produce a class of fluorescent compounds called coumarins. The different species and subspecies of sagebrush have been shown to produce different varieties and amounts of coumarins, which can be an additional biomarker for typing. Additionally, the palatability of sagebrush is positively correlated to the coumarin content indicating sagebrush foraging preferences are based on the coumarin content, underscoring the importance of positive identification of species and subspecies type.
An Ultraviolet-Vis (UV-vis) spectroscopic assay was
developed to establish additional methods for sagebrush subspecies identification based on coumarin content. Sagebrush extracts were made with Early sagebrush (Artemisia arbuscula longiloba), Wyoming sagebrush (A. tridentata wyomingensis), and an unknown composite of several sagebrush subspecies. The extracts were made in water, ethanol, and hexane. The fluorescent intensity of each extract was measured and compared to the fluorescent intensity of several standard coumarin solutions at known concentrations. The fluorescent intensity of the Early sagebrush was significantly higher than that of the unknown composite and Wyoming sagebrush, allowing one to distinguish the two subspecies from one another. As many sagebrush obligates prefer Early sagebrush to nearly all other sagebrush subspecies, the assay was determined to be effective for identifying preferable sagebrush for foraging purposes.
“Colorimetric Sensing of DNA via Catalytic Dispersion of Gold Nanoparticles”
Luke Knudson
Lee Lab, Boise State University
A colorimetric DNA biosensor was built and tested using gold nanoparticles integrated into a DNA amplification network and aggregated onto polymer microspheres.
Previous aggregation based sensors rely on forming linkages between nanoparticles to induce a plasmonic coupling affect as a visual marker. In this sensor a signal is produced from the catalytic disaggregation of gold nanoparticles. A single target DNA strand can catalyze the release of multiple gold nanoparticles from the polymer microsphere aggregates.
Gold nanoparticles were functionalized with thiol modified DNA and integrated into a DNA amplification network that releases gold nanoparticles in the presence of target DNA. A biotin modified linker strand was used to attach the functionalized gold nanoparticles to streptavidin coated polymer microspheres. The completed assembly was tested with various concentrations of target DNA. The amount of gold nanoparticles released from the aggregates was measured using UV-Vis spectroscopy. A signal was produced from the sensor at target concentrations as low as 1 nM.