Bad news for oak forests of the Northwest; sudden oak death was detected in Oregon last month. Though it's unclear how it arrived, it's feared that this killer spread from the central California coast, where it has destroyed thousands of oak trees since 1994. A recent discovery of the infectious agent, the fungus Phytophthora ramorum, in rhododendrons has provided the first clue in what up until now has been the mysterious appearance of this deadly pathogen. Although Phytophthora's European rela

Organisms need to sense their environment. By sensing, they can develop, heal wounds, protect against invaders, and create blood vessels. Chemotaxis, or directional sensing, allows cells to detect chemicals with exquisite sensitivity. Some chemotactic cells can sense chemical gradients that differ by only a few percent from a cell's front to its back. Although discovery of the molecule types involved in chemotaxis, as with other kinds of cell signaling events, has mounted, the details of how thi

In 1997, to the surprise of many researchers, mitochondria reclaimed the limelight of apoptosis research when several groups observed that cytochrome c released from the mitochondria could induce apoptosis in cell-free systems.1,2 A hot research topic decades ago, mitochondria excitement cooled in the 1970s when researchers agreed on the mechanisms of oxidative phosphorylation (ox-phos). Now, mitochondria-mediated apoptosis is believed to be central to a number of major debilitating diseases, in

Europeans have destroyed 4.5 million cows since 1996, the height of the epidemic in the United Kingdom, because they were believed to be at risk for mad cow disease (bovine spongiform encephalopathy, or BSE).1 Necropsies, however, showed that only a few hundred thousand of them actually were infected.2 Had a diagnostic test for mad cow disease existed when this epidemic erupted, these numbers might have been different. But no such test did exist. The only available assay was a bioassay in which

Parkinson's disease could be the perfect target for stem cell therapy. The etiology of this progressively debilitating disease is clear: scientists know what cells are affected, where those cells reside, when those cells are created during development, and what their target is. This information is reported in scores of articles on cell transplantation that use fetal cells to treat Parkinson's in animal models and people. The good news continues. New research shows that by using stem cells, sci

The rate of autism is rising. The number of reported cases has increased 10-fold in the last few decades, from 1 in 2,500 in the 1970s to 1 in 250 in the 1990s. Researchers are looking everywhere for the reason--from drinking water to the womb--with no clear-cut answer to date. In part, the increased incidence can be attributed to a broader definition of autism, which now includes milder forms of the disorder,1 as well as to better diagnostics and greater public awareness.2 But scientists don't

A small company in Pasadena, Calif., is commercializing a technology developed by scientists at the nearby California Institute of Technology to put the sense of smell at your fingertips. Using an array of 32 extendable polymers, Cyrano Sciences' handheld electronic nose will someday be capable of sniffing out anything from land mines to halitosis-causing bacteria in humans. Due to be available at the end of the year, this electronic nose will be handheld, easy to use, and fast--with applicatio

Aga2-fusion protein binding to yeast cell by Aga1. Image provided by Invitrogen. Phage display systems, reviewed in a recent issue of The Scientist,1 have proven enormously useful for the detection of protein-ligand interactions, as well as for the selection of variants with altered binding characteristics. However, limiting the utility of phage display systems are so-called expression biases against certain eukaryotic proteins, as well as the distinctly different protein processing mechanisms

Two-Hybrid Systems Studying a biological phenomenon? Which field? Well, it really doesn't matter. Whatever the area of interest, rest assured that protein-protein interactions are somehow, somewhere involved--if not directly, then as part of a structural or regulatory apparatus. Two-hybrid systems, pioneered by Fields and Song,1 are powerful systems for detecting interactions between and among macromolecules. The first systems described were for protein-protein interactions; later, the basic

Date: March 29, 1999Fragment Purification Products Table Purifying DNA fragments from gels is one of those chores that no one likes to talk about--it's not glamorous, yet it is essential for a functioning molecular biology lab. There are almost as many methods around for doing this as there are researchers. And everyone swears by his or her favorite method. The fact is that probably all methods work to some degree, and most work reasonably well. There are two basic approaches to isolating fragm

GenoSensor System, showing results of hybridization to biochip (left) and display of data using software (right). Gene amplification and rearrangements have long been known to occur in cancer cells, and the connection between these events and disease outcome is of great interest, especially in light of the relationship between HER-2/neu amplification and a poor breast cancer prognosis. It is with this backdrop that Vysis, a genomic disease management company based in Downer's Grove, Ill., has

What is it? Acrydite is a molecular chimera containing an acrylic group and phosphoramidite that can be used as a platform for oligo construction (via the phosphoramidite part) and as a vehicle to attach oligos to surfaces (via the acrylic portion). What makes this particular molecule so useful is that it attaches to surfaces in a single step--and a number of different surfaces are possible--forms a bond that is resistant to high temperatures, and leaves the attached oligo accessible for hybrid