Biological interactions form the basis for many assays; polyvalent interactions between biomolecules have been used for specific binding, immobilization, and detection. But biological affinity methods can have several drawbacks, including limited reproducibility, high background, low binding capacity, and poor stability. Prolinx Inc. of Bothell, Wash., has introduced Versalinx Chemical Affinity Tools, a synthetic affinity binding pair based on the interaction between phenylboronic acid (PBA) or

Syngene's GeneGnome Chemiluminescence imaging system Radioactive detection procedures are quickly being replaced by safer methods such as fluorescence and chemiluminescence. Re-searchers using fluorescent detection can choose from a wide array of electronic imaging equipment, but those who work with chemiluminescence have been relegated to the darkroom to process their images. With the introduction of the GeneGnome, an automated imaging system designed specifically for chemiluminescence, Syngene

Reverse Transcriptases Commonly Used for RT-PCR Reverse transcriptase-PCR (RT-PCR)--a method for assessing gene expression, detecting low copy number mRNA transcripts, and generating complementary DNAs (cDNAs) for cloning--converts an RNA template to its DNA counterpart with a reverse transcriptase enzyme. The cDNA is then amplified by PCR. Although the technique appears relatively painless, researchers using RT-PCR may encounter several pitfalls. For instance, reverse transcribing long mRNA te

Easy Estimation The dotMETRIC™ protein and nucleic acid assays from Geno Technology Inc. of St. Louis make estimating protein and nucleic acid concentration simple and quick, with no expensive equipment. To estimate protein concentration, 1 µl of protein solution is mixed with the supplied dilution buffer and spotted onto a test strip. The resultant spot diameter is proportional to the concentration of the sample. The assay takes only eight to 10 minutes to perform and can detect as

Procedure for Cyclex's Luminetics T cell activation assay The T-cell immune status of patients with conditions such as AIDS indicates disease progression. One way to evaluate T-cell immune health is to measure the proliferation of a patient's T cells in response to stimulation with an antigen or mitogen. However, these measurements typically require long incubation times and radioactive isotopes, making them unsuitable for clinical applications. Columbia, Md.-based Cylex Inc. has designed a con

Fluorescence in situ hybridization (FISH) has long been used to detect specific nucleic acid sequences in paraffin-embedded tissue sections. However, using fluorescent detection requires specialized training and expensive fluorescence microscopes. Zymed Laboratories Inc. of San Francisco has introduced the SP•T-Light™ line of chromogenic ISH (CISH) products based on its proprietary Subtractive Probe Technology (SPT™). These products provide researchers with probes and detection

Spin City Stratagene of La Jolla, Calif., is offering 25 percent off its StrataPrep(r) Total RNA Microprep Kit until September 30, 2000. The kit isolates high-quality total RNA from small quantities of cultured cells using a spin-cup format. The rapid procedure does not require phenol/chloroform extraction or ethanol precipitation. An optional on-column DNA removal step prepares samples for RT-PCR The list price for the kit is $179.00 for 50 preps; the discounted price is $134.25. To receive t

GenomicsOne's TrueBlue Cloning Scheme For the past two decades, cloners have relied on lacZ*-based color selection vectors to identify cloned inserts. These systems are based on the insertional inactivation of the lacZ* gene fragment and are (deceptively) simple. The lacZ gene encodes the ß-galactosidase (ßGal) protein, which acts on an indicator substrate to produce blue colonies. Thus, in a cloning experiment, white colonies indicate that the DNA of interest has been inserted into t

Eppendorf-5 Prime's PERFECTprep-96VAC Quad Vacuum Manifold High throughput may be the wave of the future, but most laboratories must still perform smaller-scale procedures at various steps in an investigation. For the many researchers who don't have access to automated systems for DNA purification, Eppendorf-5 Prime Inc. of Boulder, Colo., offers the PERFECTprep-96VAC Quad Vacuum Manifold, a tool for manually purifying DNA rapidly. The system is based on a time-tested alkaline lysis protocol

HeLa cell expressing CLONTECH's DsRed in mitochondria and Cyan Fluorescent Protein in the nucleus, visualized by overlaying fluorescence microscopy images Green fluorescent protein (GFP), isolated from the jellyfish Aequorea victoria, has been a valuable tool for researchers monitoring gene expression and protein distribution in living cells. Part of the appeal of using GFP to track gene expression is that it does not require addition of substrates or cofactors for detection, but is visualized

Magnetic Separation Systems Suppliers of Magnetic Microspheres for a Variety of Applications Labsystems' KingFisher Magnetic Particle Processor plunges into the magnetic separation scene. Since LabConsumer's last profile of magnetic bead technology, the use of paramagnetic particles in biological separations and detection has exploded.1 However, development of processing technologies has lagged behind refinements of the beads themselves. The instrumentation emerging within the last few years

RT Party Until July 31, 2000, CLONTECH is offering a free PowerScript™ Reverse Transcriptase 30 reaction kit with the order of any Premium RNA™ Total RNA Panels. Powerscript Reverse Transcriptase lacks RNase H activity but retains wild-type polymerase activity, making it ideal for synthesizing long cDNA fragments. PowerScript Reverse Transcriptase is guaranteed to be RNase-free. To receive this promotional offer, cite code #Q12870. CLONTECH, (800) 662-2566, www.clontech.com Scan It