Laboratory exercises for undergraduate biochemistry students are described in which changes in sugar content during fermentation of the trendy beverage kombucha are analyzed by three methods: thin layer chromatography, a 3,5-dinitrosalicylic acid assay, and a standard commercial blood glucose meter. Each of the three analyses can be completed in a…

A differential scanning calorimeter was used to study homogeneous nucleation of ice from micron-sized aqueous ammonium sulfate aerosol particles. It is important to understand the conditions at which these particles nucleate ice because of their connection to cirrus cloud formation. Additionally, the concept of freezing point depression, a topic…

Gas chromatography-mass spectrometry (GC-MS) and GC-tandem MS (GC-MS/MS) are useful in many separation and characterization procedures. GC-MS is now a common tool in industry and research, and increasingly, GC-MS/MS is applied to the measurement of trace components in complex mixtures. This report describes an upper-level undergraduate experiment…

Providing a biotechnology experience for students can be challenging on several levels, and time is a real constraint for many experiments. Many DNA based methods require a gel electrophoresis step, and although some biotechnology procedures have convenient break points, gel electrophoresis does not. In addition to the time required for loading…

Described is a conductiometric method for following the course of diffusion of aquated ions through a cellulose membrane. Several experiments using the method are described. (Author/SA)

Describes a laboratory exercise containing a practical series of experiments that novice students can perform within two hours. The exercise provides a confirmation of van't Hoff's law while placing more emphasis on osmotic flow than pressure. Students can determine parameters such as the reflection coefficient which stress the interaction of both…

Presents a simple and reliable technique using commonly available equipment for monitoring carbon monoxide in automobile exhaust. The experiment utilizes a gas chromatograph and a thermal conductivity detector (TCD). (DDR)

Presents demonstrations of chemical reactions by employing different features of various compounds that can be altered after a chemical change occurs. Experimental activities include para- and dia-magnetism in chemical reactions, aluminum reaction with base, reaction of acid with carbonates, use of electrochemical cells for demonstrating chemical…

Presents nine physics notes for British secondary school teachers. Some of these notes are: (1) speed of sound in a steel rod; (2) physics extracts-part four (1978); and (3) a graphical approach to acceleration. (HM)

Describes some undergraduate laboratory experiments in acoustics which involve the analysis of speech and musical instrument sounds and the general analysis of the frequency range of complex sounds. (HM)

Describes a technique for the supercooling of water, for use in the science classroom, involving adding common salt to a mixture of ice and water. Several investigations are included for use during (and after) the process of supercooling. (DS)

Outlines procedures for demonstrating and preparing a permanent slide of sister chromatid exchanges and recombination events between the two chromatids of a single chromosome. Provides the name of an additional resource for making preparations of exchanges. (RT)

Presents a laboratory experiment on determining the molecular weight of an unknown molecule by using gel filtration chromatography. Describes the procedure and lists required materials. (YDS)

Presents the following three biology notes: (1) a low cost variable temperature incubator; (2) projects on the ecology of freshwater mussels (Unionidae); and (3) studies on urease. (HM)

Presents 12 chemistry notes for British secondary school teachers. Some of these notes are: (1) a simple device for testing pH-meters; (2) portable fume cupboard safety screen; and (3) Mass spectroscopy-analysis of a mass peak. (HM)