Dental faculty responses (N=332) to a survey concerning use of rubber dams for excluding fluids from the working field in operative dentistry procedures indicated students receive adequate instruction in rubber dam use and are proficient at graduation, though motivating students to its use is problematic and patient resistance a factor. (MSE)

Describes an experiment producing a visible spectrum with inexpensive equipment available in the physics classroom. Discusses some related equations, apparatus settings, and instructional methods. (YP)

Described is a simple technique for isolating DNA from halophilic bacteria. Materials, procedure, and additional experiments are outlined. It is stated that the DNA obtained will be somewhat contaminated with cellular proteins and RNA. Offers a procedure for greater purification. (RT)

Described is an activity in which students are able to determine that DNA can be transferred between bacteria and should be able to predict the type of DNA transferred. Methods, materials, and results are discussed. (CW)

This article describes how pasteurized milk can act as a growth medium for bacteria and provide an ecosystem for scientific inquiry. Included are objectives, materials, procedures, questions and a discussion of expected results. (CW)

Provides historical background, descriptions, uses and basis for identification of diatoms. Explains collection, dry-mount cleaning, and preparation procedures of the algae. Cites additional resources. (RT)

Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

The effects of temperature and pressure on the collapsing of soda cans are discussed. The use of various temperatures and substances for the cooling bath are described. (KR)

A procedure that allows students to view an entire bacterial growth curve during a two- to three-hour student laboratory period is described. Observations of the lag phase, logarithmic phase, maximum stationary phase, and phase of decline are possible. A nonpathogenic, marine bacterium is used in the investigation. (KR)

A study investigated the efficacy of glutaraldehyde and several other disinfectants for disinfecting teeth to be used for teaching and research, as an alternative to autoclaving for teeth with amalgam restorations. Results indicate that formalin was the only disinfectant that penetrated tooth pulp chambers in effective antimicrobial…

An exercise that uses a common bacterium, E. coli, in great numbers, to detect a demonstrable change in the ability of some cells to become resistant to the common antibiotic streptomycin is presented. The procedure for preparing and pouring the gradient antibiotic plates is provided. The advantages of using the Basic Fuchsin in the agar are…

Rapid-cycling brassicas can be used in the classroom to teach concepts such as plant growth, tropisms, floral reproduction, pollination, embryonic development, and plant genetics. Directions on how to obtain them for classroom use and how they may be grown are included. Practical physiology and genetics exercises are listed. (KR)

Presents a protocol that can be used to discover that S. marcescens produces a bright red pigment when exposed to one temperature condition and does not produce this color under other conditions. Enables students to connect gene expression and environmental changes. (DDR)

Describes an experiment in which the density of solutions of known sugar concentrations is measured. Data are then used to determine sugar content in commercial beverages. (DDR)

Presents a relatively short, simple, safe, and visual method for student preparation of chlorine, bromine, and iodine using reactants and glassware that are easy to obtain and handle. (WRM)