For high-throughput screening and crystallography studies, it is often necessary to express large quantities of protein--a process that is complicated if the protein is toxic to the cells in which it is expressed. To combat this difficulty, transcription of the gene of interest is repressed while the cells are grown to a high density and then induced by the addition of reagents such as IPTG or tetracycline. Although chemical induction has been successfully used to regulate protein expression for

Bio-Nobile Oy of Turku, Finland, has introduced the PickPen™, a novel magnetic particle transfer device. Unlike traditional magnetic separation methods, which generally require aspiration of liquids after separation of bound materials via a magnetic stand, the PickPen removes the particles of interest themselves. First a retractable magnet is inserted into the disposable tip of the PickPen device. The tip is dipped into the sample and removed after the magnetic particles bind. Particles ar

Pierce Chemical Co. of Rockford, Ill., has introduced the UnBlot™ Chemiluminescent In-Gel Detection Kits for detection and visualization of specific proteins. Unlike Western blotting, the technology permits detection of protein directly in the gel, eliminating transfer and blocking steps. The UnBlot kits reduce post-electrophoresis detection time to as little as four hours. Additionally, the technology is compatible with stripping and reprobing protocols, allowing users to reprobe and reop

The most common method for measuring cell proliferation (see profile, page 27) monitors the metabolism of a yellow tetrazolium salt (MTT) to blue-colored formazan. Unfortunately this is a time-consuming endpoint assay, precluding kinetic studies. Bedford, Mass.-based BD Biosciences-Discovery Labware has developed a novel detection system that solves this problem. The BD Oxygen Biosensor uses an oxygen-sensitive fluorescent dye (tris-1,7-diphenyl-1, 10-phenanthroline ruthenium (II) chloride) embe

Berthold Detection Systems of Pforzheim, Germany, has introduced the Luminescence TestPlate for the testing and validation of microplate luminometers. Identical in size to a standard 96-well microplate, the device tests the reproducibility, changes in sensitivity, and changes in dynamic range of luminescent detection systems. The Luminescence TestPlate is supplied with a rechargeable battery and evaluation software. Berthold Detection Systems' products are distributed in the United States by Zyl

While new technologies in the fields of proteomics and genomics appear almost daily, histotechnology has remained largely unchanged since its development in the mid-1800s. Tissues are fixed, embedded in wax, sectioned, and stained as needed--a labor-intensive process that generates two-dimensional glass slides that must be viewed one at a time. An anatomical pathologist by training, Russell Kerschmann, founder and president of Corte Madera, Calif.-based Resolution Sciences Corp., is intimately f

PCR Enhancement Products Courtesy of RedasoftRedasoft's Visual Cloning 2000 includes primer design tools. Courtesy of Sigma-AldrichDirect loading of PCR products onto an agarose gel using Sigma-Aldrich's REDTaq. The art of PCR isn't hard to master. An abundance of products, ranging from relatively low-cost reagents to sophisticated optimization software, exists to meet most, if not all, PCR challenges. This profile looks at commonly used additives, PCR optimization kits and protocols, softwar

Make way for the Age of SAGE. Introduced in 1995 by Kenneth Kinzler and Bert Vogelstein of the Johns Hopkins University in Baltimore, Md., SAGE™, or Serial Analysis of Gene Expression, is a quantitative method of gene expression analysis based on the idea that an mRNA transcript can be identified by just a short (9-14 base pair) subfragment.1 In the technique, mRNA is isolated, copied into cDNA, tagged at the 3' end with biotin, and then cut with a restriction enzyme. The tagged fragmen

Madison, Wis.-based Novagen's ColiRoller™ plating beads replace the "hockey stick" method of bacterial plating. Bacteria are commonly spread on agar plates with a bent glass rod that must be immersed in ethanol and placed briefly in an open flame before use; this method can result in uneven spreading and is tedious when preparing multiple plates. ColiRoller beads are a more efficient alternative--simply pipette cells onto a plate, add 10-20 beads, and tilt the plate back and forth to sprea

Courtesy of Amersham Pharmacia BiotechThe Ready-To-Run separation unitUntil December 31, 2001, Amersham Pharmacia Biotech of Piscataway, N.J., is offering a free 24-reaction Ready-To-Go™ PCR beads kit with the purchase of a Ready-To-Run™ separation unit. The new Ready-To-Run separation unit is an agarose gel electrophoresis system for the rapid screening of PCR products. The system is expandable for higher- throughput applications. Ready-To-Go PCR beads are room-temperature stable be

From 2-D electrophoresis to microscopy, much of the data generated in today's laboratories is image-based. Until recently however, there was no way to efficiently search the contents of images and to correlate them with other types of data. To address this problem, two companies have developed systems that bring the full power of the informatics revolution to bear on visual data. According to Suzanne Mattingly, vice president of marketing at Redwood Shores, Calif.-based Scimagix, up to 70 perc

The days of the paper lab notebook might be numbered. As data acquisition and analysis move further into the electronic world, researchers will most likely rely more heavily on electronic media to manage their data. Enter the free Internet-based research management systems software specifically designed for scientists by Metazoa Systems of San Francisco. With only the click of a button, scientists can upload and retrieve images and other electronic files and archive notes or protocols in an org