With the enormous reliance on plastics in the world today, bisphenol A, an additive used in the synthesis of many plastics, such as polycarbonate, has been found almost everywhere in our environment including in soil, in natural waters, and inside organisms including humans. A multidisciplinary experiment is presented that involves using flatworms…

Many science departments encourage students to gain experience conducting research. However, finding ecological research projects that allow students to test a hypothesis in the field, over the relatively short time span of a semester, can be challenging. This article describes an inquiry-based research activity examining the influence that urban…

Newton's law of cooling describes an object whose temperature decreases exponentially with time. Because of its many applications, it is a frequent topic of introductory physics labs. In this article, I describe an experiment designed for the freshman year algebra-based physics course that applies this law to answering the question, "Why…

Proficiency with instrumental analysis via GC-MS is an important skill for chemistry students. The application of analytical techniques and fundamental theoretical principles to real-world problems can be valuable learning exercises for undergraduates which can also improve their analytical thinking skills. Xylitol is generally considered safe for…

In this teaching laboratory, the students are directed in an exercise that involves designing and performing an experiment to determine estrogen's role in regulating delayed implantation (diapause) in female rats. To encourage active participation by the students, a discussion question is provided before the laboratory exercise in which each…

Polychlorinated biphenyls (PCBs) are a family of synthetic chemicals consisting of carbon, hydrogen, and chlorine atoms. PCBs have been produced commercially since 1929 in hundreds of industrial applications. Their continued production in the United States was phased out in the late 1970s, and strict disposal guidelines were regulated as adverse…

Galen of Pergamon (130-200 A.D.) was an accomplished showman and scientist who made enormous advancements in the understanding of the heart, nervous system, and mechanics of breathing. These advancements were often achieved during impressive public "performances" of vivisection on Barbary apes and other living animals. These "shock…

A laboratory experiment is described that extracts the tetrapyrrolic teal-colored biliverdin IXa, as its dimethyl ester, from commercially available emu eggshells. The extraction of ~10 mg samples of biliverdin is simple and requires two 3 h lab periods: A two-step acid digestion and liquid-liquid extraction, followed by short silica gel flash…

A series of three practical sessions are designed to give students firsthand experience with the preparation of natural product extracts and assay using a live tissue preparation. Areca or betel nuts are the seeds from the fruit of the "Areca catechu" palm tree that is known to contain a number of pharmacologically active alkaloids. The…

Analysis of mercury in fish is an interesting problem with the potential to motivate students in chemistry laboratory courses. The recommended method for mercury analysis in fish is cold vapor atomic absorption spectroscopy (CVAAS), which requires homogeneous analyte solutions, typically prepared by acid digestion. Previously published digestion…

All the cells of higher organisms have the same DNA but not the same proteins. Each type of specialised cell that forms a tissue has its own pattern of gene expression and, consequently, it contains a particular set of proteins that determine its function. Here, we describe a laboratory exercise addressed to undergraduate students that aims to…

Optimal foraging theory attempts to explain the foraging patterns observed in animals, including their choice of particular food items and foraging locations. We describe three experiments designed to test hypotheses about food choice and foraging habitat preference using bird feeders. These experiments can be used alone or in combination and can…

"In situ" hybridization is a widely used technique for studying gene expression. Here, we describe two experiments addressed to postgraduate genetics students in which the effect of transcription factors on gene expression is analyzed in "Drosophila embryos of different genotypes by whole-mount in situ hybridization. In one of the…

We have developed a semester-long laboratory project for an undergraduate immunology course in which students study multiple aspects of macrophage biology including differentiation from progenitors in the bone marrow, activation upon stimulation with microbial ligands, expression of cell surface markers, and modulation of cytokine production. In…

This adaptable graduate laboratory course on protein purification offers students the opportunity to explore a wide range of techniques while allowing the instructor the freedom to incorporate their own personal research interests. The course design involves two sequential purification schemes performed in a single semester. The first part…