Food scientists, agronomists, and chemists frequently need to know the amount of calcium present in a variety of solutions. Different solutions, however, may require different electrodes. A new Calcium Ion-Selective Electrode (ISE) from Hach Co. can measure calcium in almost all aqueous sample types, including colored and turbid samples, according to the manufacturer. Applications include measurement of calcium in milk, wine, boiler feed-waters, feeds, plant tissues, and beer. The Hach Calci

Researchers who analyze and isolate specific proteins and nucleic acids often find that gel electrophoresis is the method of choice for these experiments. Proteins or nucleic acid mixtures are separated into individual species based on differences in molecular weight as they migrate through an acrylamide or agarose gel in the presence of an electric field. In addition to serving as an analytical tool, individual proteins and nucleic acids, once separated, can then be isolated in pure form by

Beckman Instruments Inc. now markets the new FUTURA(trademark) Plus combination electrodes, featuring a rugged bulb line, a quick temperature response STAR(TradeMark) series, a flat bulb electrode, and several permanently filled electrodes for special applications in electrochemistry. The rugged bulb, STAR, and flat bulb electrodes come with the new Beckman pHresh Performance Pac, which protects the pH sensing bulb from contamination with dried salts and ensures that the electrode is always r

Applications are growing rapidly in basic research and clinical investigation for the detection with labeled DNA probes of specific DNA Sequences present in cells via in situ hybridization. Currently, it is necessary to radiolabel the DNA probe prior to hybridization, and then perform autoradiography on the specimen that has been probed. Radiolabeling (via such techniques as P32 nick-translation) is costly, time-consuming, and potentially hazardous. In addition, autoradiography often requires lo

A central area of investigation in cancer research and therapeutic treatment is the role of multidrug resistance (MDR) in neoplastic cells to a variety of chemotherapeutic compounds. Elevated levels of Pglycoprotein, an integral membrane protein that acts as a drug efflux pump, have been associated with the phenomena of MDR. High levels of P-glycoprotein expression have been identified in a variety of cell lines selected for resistance to various chemotherapeutic drugs. In addition, elevated lev

Over the last several decades, a detailed description of the, fine struc " ture of cells and tissues has emerged, due in a large part to transmission electron microscopy (TEM). With improvements in microscope design, sectioning techniques, and fixation and staining methodology, scientists can now examine biological structures with nanometer resolution. In addition, regularly spaced structures, such as cytoskeletal polymers, can be described in molecular detail via electron diffraction. Desp

Densitometers are used routinely in molecular biology and biochemistry to quantify nucleic acid or protein bands and spots on autoradiograms, stained gels, and transfer membranes. The performance of the densitometer can have a profound effect on the validity of such measurements. Molecular Dynamics, headquartered in Sunnyvale, Calif., introduced the Model 300A Computer Densitometer in May 1988: The device is fundamentally different from other densitometers in that it combines several distinc

A wide variety of cellular processes—including cell division, growth regulation, neural transmission, and ionic regulation—are regulated via transient shifts and/or steady-state shifts in the levels of molecules acting as signal transducers (for example, calcium flux, pH shift, and receptor binding). In order to investigate the mechanics of these complex multicomponent processes, bioscientists need to pinpoint and quantitate these event(s) in living cells and tissues. A variety

Scientists working in genetic engineering and pharmaceutical research often find it necessary to obtain highly purified molecules from complex biochemical mixtures. Column chromatography. most often the method of choice, is a time-consuming, labor-intensive, and expensive process. Now, a new method has emerged that is superior to column chromotagraphy in all of these respects. Called radial flow chromotography, this alternative chromatographic method, was recently introduced by Sepragen Corp.,

In the not-too-distant past, scientists in biological research found themselves burdened with the time-consuming tasks of developing, purifying, and characterizing the antibodies they worked with in the lab. But today monoclonal antibody technology has eased this burden by facilitating the production and enhancing the quality of antibodies currently in use. Development of the advanced technology is especially welcome, since during the last decade the use of antibodies as a tool in basic and