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An electrical biosensor is described that can continuously track morphological changes of adherent cells providing quantitative data from both sparse and confluent cultures. The method is capable of detecting vertical motion of cells of the order of 1 nm, much below the resolution of an optical microscope.
New products for the cell biologist worth noting this week include a nonradioactive method for detecting cell culture contamination, a medium for the production and maintenance of B-cell hybridomas and a high-pressure homogenizer.
Rapidly expanding personal libraries benefit greatly from bibliographic software; new programs try to take into account each researcher's individual needs.
Event-recording software, a molecular modelling package, graphics toolkits, image processing and analysis packages, and a collection of high-tech hardware options are featured.
News from the marketplace this week features a fluorescence imaging system for recording intracellular ion concentrations, a multichannel tissue bath stimulation system and flow-through sensors for organ perfusion studies.
A comparison has been made between manual and automated DNA sequencing procedures to evaluate the ability to distinguish mixtures of wild-type and mutant sequences. Quantitative detection of such mixtures of HIV-1 drug resistance mutations was best achieved using an automated system that uses fluorescent-labelled sequencing primers. This procedure has a wide range of applications in clinical research, including heterozygote analysis. Software that automatically reports mixed-base positions is presented.
By two-dimensional (2-D) DNA typing a restriction enzyme digest of genomic DNA can be resolved on the basis of both size and base-pair sequence and subsequently analysed by repeat probe hybridization to reveal sequence variants at multiple genomic sites in parallel. The system has been partly automated and allows for large-scale comparative analysis of complex genomes in a cost-effective manner.
>A system is described for accurately translating the positive signal, obtained after hybridization of high-density colony filters, into clone coordinates. Calibration marks are made on the filter at the same time and in register with the clones. A combination of digitizing tablet and software allows for the retrieval of clone coordinates directly from the autoradiograph.
This week's sampler includes a new kit for the rapid purification of polymerase chain reaction (PCR) products, a new matrix for isolating PCR-quality DNA and a kit for PCR amplification of the 5' ends of cDNAs.
The simple aggregation of pluripotent ES ßcells with morulae-stage embryos can result in viable chimaeras at a similar frequency to that of blastocyst injection. The savings in time and equipment inherent in the aggregation techniques, however, make this approach well worth considering.
Cell culture systems for the growth of endothelial cells and keratinocytes, a reagent for the removal of free label from antibody-label conjugate preparations and a radiochromatography flow monitor are featured this week.
Nearly 240 exhibitors are expected to gather in Chicago next week for the 206th National Meeting of the American Chemical Society, some of whom are featured below.
New modes of detection featured this week include a new crosslink immunoassay for bone research, a western blot kit for detecting autoantibodies to nuclear and cytoplasmic antigens, and an optical biosensor device.
High density peptide and oligonucleotide chips are fabricated using semiconductor-based technologies. These chips have a variety of biological applications.
Featured this week — a new transfection reagent, a quantitative PCR system, new vector systems, fluorescent ion indicators, ionophores and probes for cell signalling, and two new fluorescence-based imaging instruments.
Among this week's tools for separation – a modular capillary electrophoresis system with in-built autosampler, chromatography data systems, and columns for chiral separations and the separation.
Featured this week — a fusion protein cleavage system, an enzyme immunoassay kit for the quantitative determination of 12(S)-hydroxyeicosatetraenoic acid levels and a new mRNA detection system.
