Articles by Barbara Cunningham

It is often said that necessity is the mother of invention. In the world of bioinformatics, the need to examine and manipulate large volumes of sequence data begat specialized computer software to handle these tasks. These programs vary in terms of ease-of-use, power, and functionality. Yet they can each perform some or all of the following functions: DNA and protein sequence entry, editing, annotation, analysis, and alignment; primer identification; map making; contig assembly; "in silico" cl

Chromatin fibers are made up of eukaryotic DNA found in the nucleus. Once considered a dull, static entity, a passive scaffold that supports many interesting cellular processes, chromatin structure is now known to be dynamic. It changes in an orchestrated way, responding to the interchange and modification of proteins that associate with and comprise it. At the heart of chromatin's design is the nucleosome, a complex of DNA wound around an octamer containing two molecules each of histone protein

As the complete human genome sequence emerges, research shifts from questions of genomics to those of proteomics--determining the function of individual gene products and mapping global gene expression patterns. Gene expression patterns change continually during the course of tissue development and differentiation. The expression of different gene products at any given time within a particular cell defines the cell's characteristics and helps determine how it will react to external stimuli. Alte

Cell Proliferation Assays Suppliers of Cell Proliferation Assays Courtesy of Zymed LaboratoriesMouse anti-PCNA (PC10)-stained colonic mucosa. Scientists often require rapid and accurate measurement of viable cell number and cell growth. These researchers traditionally assess cell viability via membrane integrity (e.g., trypan blue exclusion), and cell proliferation via the incorporation of labeled nucleotides (e.g., [3H]-thymidine) into newly synthesized DNA during cell division. Work to im

Nearly all scientists involved in basic biomedical research are familiar with the "Red Book" (Current Protocols in Molecular Biology)1 and Molecular Cloning: A Laboratory Manual.2 These well-known, time-tested books are still considered "bibles" in research laboratories, containing a wide range of basic techniques used by most life scientists. However, as scientific studies and experimental designs become more intricate and specialized, so do the techniques involved. As a result, detailed, "spec

Available Two-hybrid Systems Graphic: Leza BerardoneGenome sequencing has produced a vast supply of proteins in need of a functional identity. One way to identify a protein's function is to identify its interacting partners, because proteins often work in pairs or as part of large complexes. Scientists traditionally have used biophysical or biochemical methods (such as affinity chromatography or co-immunoprecipitation) to study protein-protein interactions. More recently, two-hybrid and phage-d

Available Competent Cell Lines Invitrogen's One Shot Kit Researchers looking for the ideal competent cell are faced with an interesting dilemma. While there is a vast market of special-function hosts that exhibit a variety and combination of mutations,1 scientists must choose carefully to take full advantage of the options and maintain the increased control that these hosts can provide. In such a market, the genotype says it all. These days, even most of the basic cloning strains are improved

Microarray enthusiasts take note: It is now possible to study relative changes in the expression levels of hundreds of proteins simultaneously thanks to the new PowerBlot Western Array Screening Service offered by BD Transduction Laboratories, a division of BD Biosciences located in Lexington, Ky. With an approach that complements the current nucleic acid methods for monitoring gene expression, this novel service analyzes cellular changes on the protein level and provides a powerful tool for pro

Induced cellular events distinguished by LumiTech's ApoGlow assay Apoptosis is an organized, energy-dependent process involving a number of well-defined pathways that lead to the death of a cell. Ultimately, these pathways converge on the mitochondria, causing changes in mitochondrial transmembrane potential that perturb cellular ADP:ATP ratios. Scientists at LumiTech Ltd. of Nottingham, United Kingdom, have shown that distinctive changes in the ADP:ATP ratio occur during cellular apoptosis and