Complementary DNA (cDNA) libraries are standard tools for gene expression studies. In theory, the library contains full-length DNA copies of every mRNA in the starting sample, in abundances representative of the original sample. In reality, however, the libraries are often missing rare clones and contain partial gene fragments, complicating subsequent analyses. Further, transferring specific cDNA clones from one vector to another--to express the protein in mammalian cells instead of in bacteri

Courtesy of Bio-Rad Laboratories  AUTOMATING DISCOVERY: Two-dimensional gel-based proteomics is traditionally derided for its technical difficulty, low-throughput, and lack of reproducibility. Instrument manufacturers have fired back with a range of automated and integrated options. Shown here is the ProteomeWorks product line. Thierry Rabilloud has been doing proteomics since long before the word proteome was even coined. For years Rabilloud, currently at the Atomic Energy Commission Re

5-Prime | Ribozymes 1. What's a ribozyme? It is a catalytic RNA molecule. That discovery won the 1989 Nobel Prize in Chemistry for Tom Cech and Sidney Altman. Eight classes of ribozymes have now been identified, including seven that modify the nucleic acid backbone: hammerhead, hairpin, HDV (hepatitis delta virus), ribonuclease P, group I intron, group II intron, and VS ribozyme. The eighth type, the ribosome's peptidyl transferase center, builds peptide bonds. 2. What's all the fuss ab

Front Page | Golden Electroporation; Recyclable Microarrays?; Rad! Volocity Goes Modular Courtesy of BTX GADGET WATCH | Golden Electroporation Scientists in high-throughput labs are no longer limited to chemical transfection technologies; thanks to BTX, they can opt to electroporate, instead. The San Diego-based company (www.btxonline.com) recently released a 96-well, gold-plated, disposable electroporation microplate--a high-throughput alternative to single-use cuvettes. Now, rather than

Courtesy of Quantum Dot Corp. Fluorescent reporter molecules are used for microscopy, real-time PCR, microarrays, and other applications. Yet most fluorescent dyes share some fundamental flaws: They are subject to photobleaching, are not very bright, and have overlapping emission and absorption spectra. Some nanotechnologists are betting that quantum dots (QDs) will eliminate these problems. QDs consist of a nanometer-scale crystalline core of semiconductor material; biologically active versi

Front Page | Better Brewing Through Chemistry; A Peel-ing Cell Culture; Worm Researchers Reach for the Stars PATENT WATCH | Better Brewing Through Chemistry The next time you have a particularly satisfying pint, you may want to thank the biochemists at Japan's Sapporo Breweries, which has patented a way to select better barley biochemically.1 Beer's qualities depend largely on two barley enzymes: b-amylase (BA), which hydrolyzes the starch molecule's penultimate linkage to produce maltos

A Standing Ovation; BioJava Percolates; As Seen on TV Courtesy of VistaLab GADGET WATCH | A Standing Ovation Studies show that routine use of a pipettor can produce repetitive stress injuries and discomfort in the neck, shoulder, elbow, hand, and wrist. Mt. Kisco, NY-based VistaLab (www.vistalab.com) decided to find out why. The company asked ergonomics experts to study how people use pipettes and to recommend design improvements that could ease the pain. The experts offered four suggestio

PATENT WATCH | Photolithography Advances Affymetrix Affymetrix, the Santa Clara, Calif.-based manufacturer of GeneChip® microarrays, has developed a new device to create microarrays, according to a recently awarded patent.1 The new technique replaces physical photolithographic masks with computer-generated ones, and will, according to the application, "significantly improve the cost, quality, and efficiency of polymer array synthesis." GeneChip arrays typically consist of hundreds of th

This past November, millions of Americans headed for the polls, exercising their right to participate in the democratic process. The Scientist also believes in the democratic process, and earlier in the year it asked readers to vote on who makes the best stuff. Lab stuff, that is--the instruments, gadgets, software, tools, and resources that make it possible, even enjoyable, to do lab research. The Web-based poll asked for free-form answers, so respondents could enter any product or company t

Image: Courtesy of the Sci Institute, NLM, and Theoretical Biophysics Group of the Beckman Institute at UIUC THE MIND'S EYE: A researcher maps the human brain using a large-scale visualization theater. Imagine standing in a room, with a three-dimensional HIV-1 protease floating before your eyes. As big as a boulder, the enzyme's craggy surface seems so close you can almost touch it. But put out your hands, and you'll touch naught but air. Welcome to the Delaware Biotechnology Institute'

Image: Courtesy of Ambion SILENCE! HeLa cells transfected with Cy3-labeled GAPDH or Scrambled siRNAs using Ambion's siPORT Lipid Transfection Agent were harvested 48 hours post-transfection. Red: Cy3-labeled siRNA; blue: DAPI-stained nuclei; green: GAPDH protein. Introduction of the scrambled control siRNA (left) had no effect on GAPDH protein expression, whereas transfection of an siRNA targeting GAPDH (right) resulted in drastic reduction in GAPDH protein levels. Much attention has bee

Image: Courtesy of Biocat SCORES OF CORES: Each tissue core on this microarray provides another datapoint that helps researchers better define the molecular characteristics of interesting genes. In 1997, Juha Kononen, a postdoctoral fellow at the National Human Genome Research Institute, was pondering the significance of the recently developed DNA microarray. He was studying genetically altered genes in cancerous cells using fluorescence in situ hybridization and immunostaining of indivi