Facilities and Equipment

Overview

About Us

The electron microscope laboratory currently houses a Hitachi S-3500N variable pressure Scanning Electron Microscope (SEM) with a resolution of 3 nm. It can examine non-conductive hydrated biological samples at a maximum pressure of 240 Pa. using a Robinson Backscattered detector in variable pressure mode. The Robinson detector is also used to examine samples using high energy backscattered electrons that emphasize atomic number differences in the sample.The SEM is also equipped with an EDAX x-ray microanalysis system (energy dispersive spectroscopy) with a liquid nitrogen free 10 mm2 silicon drift detector that can detect elements down to boron (131ev resolution). This technique is non-destructive to the sample and sensitive to elements in concentrations as low as ~1000 ppm. The system also allows the collection of x-ray area maps where each element in a non-homogeneous sample can be assigned a different color thus revealing not only the presence of a particular element but its location and abundance on the sample surface.

Research

Research in the electron microscope laboratory encompasses a wide variety of disciplines including biology, chemistry and geology. Current research involves exploring the means of infection of a specific bacteriophage (KVP40) in the marine bacterium Vibrio natriegens. The goal is to develop a marine phage host model and to explore the potential role of iron in phage infection and their importance in iron cycling in the ocean.

Recent work has also lead to the discovery of a novel potexvirus in turtlegrass (Thalassia testudinum) and discovery of a single-stranded DNA virus in spiny backed orb weavers from Florida.

Graduate student research includes the measurement of shell thickness trends in Pteropods following the Deepwater horizon spill.

Past projects have included the examination of bleached foraminifera in response to UV rays in sunlight, the discovery of viruses in marine copepods and the sizing and chemical classification of African and Saharan dust particles. The SEM has been used extensively over the years in taxonomic studies of marine microfossils because of its incredible ability to resolve morphological details that are critical in classifying organisms.

Services

Two graduate level courses are offered in alternating semesters on the theory and techniques of Transmission Electron Microscopy and a separate course on the theory and techniques of Scanning Electron Microscopy. Students are given hands on training in specimen preparation and instrument operation as well as background theory in classroom lectures. A personal project in each class assures that students have mastered the basic fundamentals of TEM and SEM.

The TEM, SEM and x-ray microanalysis instruments as well as the specimen preparation equipment are available to researchers outside the College of Marine Science, USF.

Currently the cost of using the laboratory is $90.00/hour for those outside the USF system.