A problem-solving experiment is a learning activity that uses experimental design to solve an authentic problem. It combines two evidence-based teaching strategies: problem-based learning and inquiry-based learning. The use of problem-based learning and scientific inquiry as an effective pedagogical tool in the science classroom has been well…

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…

In classroom science laboratories, unlike a real science laboratory, the teacher can guide students away from potential dead ends and toward data that are most likely to result in accurate conclusions. Sometimes, though, allowing students to pursue dead ends and to collect "bad" data can provide especially rich learning opportunities.…

The written lab report--a concise and accurate accounting of an experiment, including a summary of the procedure, presentation of the results, reasoned analysis, and thoughtful explanation--is essential to the scientific endeavor and a key expression and product of inquiry. Generally, however, students and teachers dislike these reports, the…

A recipe is a great way to learn about the procedure and the variables (or "ingredients") involved. Cookbooks are comforting and valuable: They're easy to follow, and people know what they'll get. The problem is that cookbook labs end just when things get interesting. The excitement of science is in understanding the discovery and pursuing the…

In this article, the authors describe a two-phase inquiry lesson in which students explore the catalytic activity of amylase on starch (Rungruangsa and Panijpan 1979). In the first phase, students' prior knowledge about the reaction is assessed through a set of directed prompts and small-group discussion, then challenged or reinforced as students…

Researchers at National Jewish Medical and Research Center have demonstrated that dilute bleach not only kills common household mold, but may also neutralize the mold allergens that cause most mold-related health complaints. The study, published in the Journal of Allergy and Clinical Immunology, is the first to test the effect on allergic…

Presents a set of laboratory experiments that can assist students in the detection of carbon dioxide. Offers a variation of the supported drop method of carbon dioxide detection that provides readily visible positive results. Includes background information on carbon dioxide. (ML)

A practical magnetotropism experiment with seeds is presented. The procedures, needed controls, and observations of results are described. (DF)

Using microbiology activities in the classroom is an effective way for teachers to address National Standards in the life sciences. However, common microbiology activities that involve swabbing doorknobs and hands are too risky due to the likelihood of culturing human pathogens. In addition, making sterile media and maintaining sterile conditions…

The Kirby-Bauer assay, also called the disc diffusion assay, is a standard procedure used in clinical laboratories to test the susceptibility of patients' bacterial isolates to antibiotics. In the assay, the bacteria are swabbed onto an agar plate, and paper discs impregnated with antibiotics are placed on the agar. The antibiotic diffuses from…

To integrate a research/discovery component into one course, an experiment using the sea urchin embryo system is introduced because the teacher manages only one organism and students provide the variables. The materials, handling methods, and experimental methods of the experiment are described. (YP)