Courtesy of Applied Biosystems Single nucleotide polymorphisms--variations at specific nucleotide positions in the genome sequences of two individuals--are perhaps the most common form of genetic diversity; it is estimated that 3-10 million SNPs are present in the human genome. Researchers use these markers to map disease genes, and in the burgeoning field of pharmacogenomics (personalized medicine). Such research necessarily requires the ability to genotype on a grand scale, but until recent

Until recently, scientists were largely limited in their choice of mRNA sources. For decades it was possible to isolate mRNA from eukaryotic samples, such as animal and plant cells, but it was virtually impossible to isolate bacterial mRNA. That's because bacterial transcripts lack the poly-(A) tails found on eukaryotic messages, upon which oligo-(dT) selection, the traditional eukaryotic purification technique, is based. But now researchers studying bacterial RNA have a new option. Austin, Tex

Fundamental laboratory techniques such as Northern blot analysis, RNA protection assays, in situ hybridization, and reverse transcriptase-PCR (RT-PCR) require high-quality, highly purified RNA samples. Preparing such samples is often laborious at best, because RNAses-both stable and omnipresent-can easily degrade the samples. In the past, RNA work was often left to dedicated labs, with dedicated work areas, equipment, and some very meticulous workers. Fortunately, the technology continues to evo

Premade Northern Blots Researchers interested in gene expression have at their disposal a whole host of RNA profiling tools, including Northern blotting, microarray analysis, and RNase protection assays (RPA). Each of these techniques has advantages and disadvantages, and scientists must decide which approach will best suit their particular need. A Northern blotting experiment involves the electrophoretic resolution of RNA samples on a formaldehyde-agarose gel, transfer of the RNA onto a solid

Labeled Nucleotides Complete Labeling Kits Courtesy of BioCrystal Ltd.Cancerous human colon tissue (tumor margins) showing non-transformed cells, which are stained with specifically prepared BioPixels. Not long ago, the options available to scientists for labeling nucleic acids were severely limited. Not only were researchers restricted to working with radioisotopes, but they also had to be satisfied with being able to address only the most basic questions about gene expression and localiz

Researchers have discovered that transgenic mice previously shown to outperform their normal counterparts on learning and memory tests1 are also more sensitive to chronic pain.2 This finding suggests that memory formation and pain sensation might share components of a common physiological pathway in mice, and therefore, possibly in other vertebrates such as humans. These "Doogie" mice (scientifically manipulated mice that make more than the usual amount of the NR2B subunit of the NMDA [N-methy

Microarray analysis, which allows scientists to analyze expression patterns of thousands of genes simultaneously, is the tool of the new millennium; no laboratory interested in genes and gene function can afford to ignore this technique. The technology, however, can be expensive and difficult to master, thus leaving some laboratories wary of investing in it. Now Amersham Pharmacia Biotech of Piscataway, N.J., offers the CyScribe™ First Strand cDNA Labeling Kit, designed to "enable even fir

Electroporator Suppliers Lipid Transfection Reagents - Supplemental Table not in Print Edition Virus Transduction Reagents - Supplemental Table not in Print Edition Equibio Ltd.'s CelljecT Pro system Technologies that introduce DNA and RNA into eukaryotic cells, tissues, or organisms provide opportunities to study the regulation and function of genes and proteins. The biggest barrier that these technologies must overcome is the cell membrane, which is not permeable to highly charged macromol

Until recently, researchers interested in analyzing their arrays or gels had to rely on complex software packages or manual analysis subject to human error. NonLinear Dynamics Ltd. of Newcastle upon Tyne, U.K., known to the research community for its Phoretix software, now offers TotalLab image analysis software, which combines the analyzing power of pre-existing Phoretix products with a user-friendly interface. Instead of requiring users to invest a considerable amount of time to learn the soft