Marker Gene Monthly Newsletter   

November, 2003

Volume 3, Number 11

© Copyright MGT, Inc., 2007.  Published by Marker Gene Technologies, Inc., The University of Oregon Riverfront Research Park, 1850 Millrace Drive, Eugene, Oregon 97403-1992 USA.  All rights reserved.  For information on the use or copying of the material contained in this document, please contact us at techservice@markergene.com.  Please see below for subscription information and updates.  This newsletter is labeled as an ADVERTISEMENT in accordance with the CAN-SPAM act of 2003, S.877 Public Law: 108-187.

Cell Proliferation Assays Using Labeling Probes.

CFDA-SE (Carboxyfluorescein Diacetate Succinimidyl ester) (M0013) is a lipophilic dye that is taken up by cell membranes. If cells are labelled with this dye and then allowed to grow, each daughter cell will contain half as much dye as the parent and will be half as bright. After each division the level of fluorescence will halve and so measurement of the green fluorescence can be used to monitor the number of cell divisions. In the example at right, human T cells have been labeled and stimulated – and the data allows analysis of up to 6 generations of cells, using flow cytometry.  A computer integration program can be used to determine how many cells belong to each generation.  The assay can also utilize our new biotin labeling reagents, like biotin-X, succimidyl ester (M0783) when combined with a fluorescently labeled avidin or streptavidin secondary detection molecule.  For more information about these techniques, see our web site or the references below:

• "Comparison of proliferation and rapid cytokine induction assays for flow cytometric T-cell epitope mapping." (2003) Tesfa L., Volk H.D., Kern F. Cytometry 52A: 36-45.
• “Imatinib mesylate (STI571) inhibits growth of primitive malignant progenitors in chronic myelogenous leukemia through reversal of abnormally increased proliferation” (2002) M. S. Holtz, M.L. Slovak, F. Zhang, C. L. Sawyers, S. J. Forman, and R.i Bhatia,  Blood 99(10): 3792-3800.
"Blockage of voltage-gated K+ channels inhibits adhesion and proliferation of hepatocarcinoma cells." (2003) Zhou Q, Kwan H.Y., Chan H.C., Jiang J.L., Tam S.C., Yao X., Int. J. Mol. Med. 11: 261-6.

Cell Permeant Caspase / Apoptosis Assays.

Intracellular localization of Caspase activity is critical to understanding the processes involved in apoptosis induction.  Many fluorogenic and colorimetric substrates have been developed which are designed to react with peptide sequences specific for individual caspase or cathepsin enzymes.  The peptide sequences, however, are often quite polar in nature, which can inhibit membrane permeability.  New substrates based upon the dye cresyl violet offer the ability to monitor these important enzymes intracellularly.  For more information about these new substrates, visit our web site (products M0520, M0837, M0838) or see the information in the references below.

• “DEVDase detection in intact apoptotic cells ≠using the cell permeant fluorogenic substrate, (z-DEVD)2-cresyl violet”  B. W. Lee, G. L. Johnson, S. A. Hed, Z. Darzynkiewicz, J. W. Talhouk, and S. Mehrotra (2003) BioTechniques 35:1080-1085.
• “Design and synthesis of Rhodamine 110 derivative and caspase-3 substrate for enzyme and cell-based fluorescent assay.” (2001) Bioorg. Med. Chem. Lett. 9: 39-42.
• Guzikowski, A.P., Naleway, J.J., Shipp, C.T., Schutte, R.C., "Synthesis of a Macrocyclic Rhodamine 110 Enzyme Substrate as an intracellular Probe for Caspase 3 Activity" (2000) Tet. Lett. 41: 4733-4735.

Neuraminidase Assays Using Fluorescence Detection.

Influenza epidemics are responsible for an average of approximately 20,000 deaths per year in the United States.  Neuraminidase is the second most abundant glycoprotein on the surface of influenza viruses.  Neuraminidase cleaves terminal sialic acid residues from carbohydrate moieties on the surfaces of host cells and influenza virus envelopes; this process promotes the release of progeny viruses from infected cells.  Zanamivir and oseltamivir, both approved in 1999 by the U.S. Food and Drug Administration, are members of a new class of antiviral agents that selectively inhibit the neuraminidase of both influenza A and B viruses.  Marker Gene is introducing a new substrate, Res-5NAcNeu (resorufin 5-acetamido-3,5-dideoxy-a-D-glycero-D-galacto2-nonulopyranosiduronic acid and a new assay kit based upon release of the highly red-fluorescent dye resorufin.  For more information about these new reagents and assays and neuraminidase, see our web site and the references below.

• “Influenza type A virus neuraminidase does not play a role in viral entry, replication, assembly or budding.”  Liu C, Eichelberger MC, Compans RW, Air GM. J. Virol. (1995) 69:1099-1106.
• “Sialidosis: delineation of subtypes by neuraminidase assay.” O'Brien JS, Warner TG. Clin Genet. (1980) 17(1): 35-8.
•   “Neuraminidase Inhibitors for Treatment of Influenza A and B Infections.” Andrea G. Winquist, M.D., Keiji Fukuda, M.D., M.P.H., Carolyn B. Bridges, M.D., Nancy J. Cox, Ph.D.  MMWR December 17, 1999 / 48(RR14);1-9.
• “Neuraminidase inhibitors for preventing and treating influenza in children.” Matheson NJ, Symmonds-Abrahams M, Sheikh A, Shepperd S, Harnden A.  The Cochrane Library, Issue 4, 2003. Chichester, UK: John Wiley & Sons, Ltd.

 Microbial Biosensors Using lacZ Reporting.

Many new biosensors have been developed that incorporate the coupling of a biological material with a microelectronic device to enable detection of substances in body fluids, water or even in air. David Walt’s group at The Max Tishler Laboratory for Organic Chemistry at Tufts University recently developed a live cell array biosensor that was fabricated from immobilized E. coli bacterial cells on the face of an optical imaging fiber containing a high-density array of microwells. Each microwell contained a single bacterium that was genetically engineered to respond to mercury contamination. The genetically modified E.coli strain, contained the lacZ reporter gene fused to the heavy metal-responsive gene promoter zntA. Using the fluorogenic reagent fluorescein di-b-D-galactopyranoside (M0250), a response of 100nM Hg⁺² could be detected after a 1 hour incubation. The optical imaging fiber was flexible and the sensitive biosensor platform can be used to monitor the expression other reporter genes and accommodate a variety of sensing strains.  For more information about this assay and other optical biosensors see the references below:

•   “Optical imaging fiber-based live bacterial cell array biosensor.” (2003) Biran I, Rissin DM, Ron EZ, Walt DR. Anal Biochem. 315(1):106-13.
• “Microbial whole-cell sensing systems of environmental pollutants” (2003) S. Belkin Cur. Opin. Microbiol. 6:206–212
• “Reporter gene bioassays in environmental analysis.” (2000) Kohler S, Belkin S., Schmid R.D. Fresenius J. Anal. Chem. 366: 769-779.
  
  

Visit Us at the American Society for Cell Biology Meeting in San Francisco.

Marker Gene will be presenting several papers at the 43^rd Annual Cell Biology Meeting in San Francisco, December 13-17, 2003 at the Moscone Convention Center.  These include new chemiluminescent assays for lacZ, as well as new luciferase and GUS systems for cell regulation.  For more information, please visit the Society’s web site at www.ascb.org. 

• “β-Glucuronidase Mediating Drug Delivery System in LFY::GUS Arabidopsis thaliana.” L. Tsai, M. Braden, T. Neff, J. J. Naleway, Presentation Number: 2200, Poster Board Number: B671. (Tuesday, 12/16, 12:00 Noon)
• “New β-Galactosidase Chemiluminescent Live Cell Assay System.” L. Tsai, B. Giri, H. R. Toben, J. J. Naleway, Presentation Number: 2621, Poster Board Number: B352. (Wednesday, 12/17, 1:30 PM)
• “New Luciferin Analogs for Monitoring Cloned Luciferase Activity.” L. Tsai, A. P. Guzilowski, J. J. Naleway, Presentation Number: L277, Poster Board Number: L277. (Wednesday, 12/17, 12:00 Noon)
  
  

2004-2005 Catalog Will Be Available Soon.

The 2004-2005 edition of the Marker Gene catalog is in production.  Many new products and kits, additional literature references, data and protocols will be included, as well as new information about our old products.  Be sure to add your name to our mailing list.  Please visit our Web site and fill out our Customer Information Form, or e-mail us at techservice@markergene.com and we will have a copy sent out to you.
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Compare Our Quality. 

Marker Gene strives to offer our customers products of the highest quality and at the best possible prices.  Our years of experience allow us to provide timely products for less cost to you.  See our latest Price Comparison Chart that compares our prices with those from several alternate sources, to see if you can save money by switching to Marker Gene (http://www.markergene.com/crossref.htm).  Or visit our website at www.markergene.com and click on the link “COMPARE”.  We think you will appreciate our efforts to keep costs low and maintain excellent quality of our products for your research.  For more information about any of our products, simply telephone us toll free at 1-888-218-4062 or contact us by e-mail at techservice@markergene.com.  We will be happy to send you more about our products and their specifications.

CONTRACT  RESEARCH@markergene.com

Marker Gene Technologies, Inc. has the expertise to perform contract research with you on your project. We have worked with many biotechnology and pharmaceutical companies on successful, proprietary and patented projects.

Contract Research and Development Capabilities in the following areas:

• Established in 1993 at the University of Oregon Riverfront Research Park.
• Screening Assay Development for HTS and uHTS
• Chemical and Cellular Assays – High-Content Screening.
• DNA/RNA (genomics) and protein (proteomics) labeling and assay development.
• Pharmaceutical Intermediates - design, synthesis, and in vitro testing in mammalian cell culture.
• Specializing in Carbohydrate, Lipid, Peptide, and Nucleic Acid Chemistries.
• Fully equipped laboratories (Biochemistry, Chemical Synthesis, Tissue Culture, Analytical).
• Confidentiality, help in patent preparation and filings.

Contact us by telephone at (888) 218-4062 or (541) 342-3760 or FAX us at (541) 342-1960 or you can write to us at  Contract Research, Marker Gene Technologies, Inc., 1850 Millrace Drive, Eugene, Oregon 97403-1992 or contact us by e-mail at: techservice@markergene.com

Marker Gene Accepts Major Credit Cards.

Place your orders now, using Master Card or Visa and save time and money!  Our Customer Assistance Staff can now accept either Master Card or Visa Credit Card orders, securely by telephone (toll-free) at 1-888-218-4062 (Domestic orders only).   We will continue to accept Institutional Purchase Orders for our products, online or by FAX at 1-541-342-1960.  International customers should contact us by e-mail, post or telephone for more information about International Distributors and ordering.  For information on pricing for individual products, or for a quote on bulk quantities of our products or kits, please contact our technical assistance staff at techservice@markergene.com.   We will be happy to assist you. 

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