Marker Gene Monthly Newsletter   

February, 2003

Volume 3, Number 2

© 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.

Removal of Marker Genes.

Marker genes find numerous applications in animal and plant systems, but can also cause consumer concern when used in commercial products or add regulatory requirements from the presence of "excess" exogenous DNA.  Several methods have recently been introduced to remove marker genes in plants, using site-specific recombination systems (e.g., lox/Cre recombinase, Flp recombination target (FRT)/Flp recombinase, or Rs/R recombinase) and by using an inducible promoter system (e.g. for b-estradiol) for the recombinase gene.  In these recombination schemes, the marker gene is flanked by recombination sites, such as lox, FRT, or Rs, which specifically interact with a recombinase protein (e.g., Cre, Flp, or R, respectively).  This interaction promotes recombination between the sites and deletes the marker DNA from the host genome.  For more information about these techniques see the references below.

• David W. Ow “The right chemistry for Marker Gene removal?” (2001) Nature Biotechnol. 19(2): 115 – 116.
• Zuo, J., Niu, Q.-W., Moller, S.G. & Chua, N.-H. “Chemical-regulated, site-specific DNA excision in transgenic plants.” Nat. Biotechnol. 19, 157-161 (2001).
• Sugita, K., Kasahara, T., Matsunaga, E. & Ebinuma. H.” A transformation vector for the production of marker-free transgenic plants containing a single copy transgene at high frequency” Plant J. 22, 461-469 (2000). 
  

Small Molecule Activator of Caspase-3.

Professor Xiaodong Wang, and co-workers at the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX have identified a small molecule activator of apoptosis, -(trichloromethyl)-4-pyridineethanol (PETCM), using high-throughput screening in a panel of cancer cells in culture.  PETCM was found to be a selective activator of caspase-3.  Caspase-3 is an important member of the family of enzymes implicated in the initial events of programmed cell death. The identification of these types of active compounds, point the way toward understanding the death initiator processes in tumor cells (two proteins were implicated in the present study), and may lead to new types of chemotherapies for intractable cancers.  For more information about this work, see the references below.

• “Distinctive Roles of PHAP Proteins and Prothymosin-a in a Death Regulatory Pathway”, X. Jiang, H.E. Kim, H. Shu, Y. Zhao, H. Zhang, J. Kofron, J. Donnelly, D. Burns, S.C. Ng, S. Rosenberg, X. Wang, Science 299 (2003) 223-226.
• “Apoptosis: Life and Death Decisions” D.W. Nicholson and N.A. Thornberry, Science 299 (2003) 214-215.

Quantum Dot Fluorescence Applications.

Quantum dots (Qdots) are polymer-coated beads that contain nanometer scale microcrystals of semiconductor material (cadmium selenide).  Arising from the solar energy research (photovoltaic cell conversion studies) of the 1980’s, they can be excited at a wide range of wavelengths (300-500nm) and produce bright fluorescence emission, with the color dependent upon the size of the contained nanocrystals.  In addition, they are much more photostable than typical fluorescent dyes.  Many quantum-dot bio-conjugates have been prepared and used in cell labeling studies, and even intracellularly, with uptake by endocytosis.  For more information, see the references below.

• Rosenthal, S.J., Tomlinson, I., Adkins, E.M., Schroeter, S., Adams, S., Swafford, L., McBride, J., Wang, Y., DeFelice, I.J., Blakely, R.D., “Targeting Cell Surface Receptors with Ligand Conjugated Nanocrystals.” J. Am. Chem. Soc. 124(17):4586-4594 (2002).
• Åkerman, M.E., Chan, W.C., Laakkonen, P., Bhatia, S.N., Ruoslahti, E., “Nanocrystal Targeting In Vivo.” Proc. Nat’l Acad. Sci. USA 99:12617-12621 (2002).
• Watson, A., Xingyong, W., Bruchez, M., “Lighting Up Cells with Quantum Dots.” (2003) Biotechniques 34(2): 296-303.

Stems Cells found Totipotent by lacZ Staining. 

Dr. Diana Clark and colleagues at the Medical Nobel Institute in Stockholm, Sweden traced the differentiation of neural stem cells by lacZ transfection and staining.  They found these cells could be induced to differentiate into most of the cells of the body.  This work is promising for use of stem cells to potentially re-populate damaged tissue after stroke or spinal cord injury or aide in regenerating tissues in multiple sclerosis, diabetes or neurodegenerative diseases.  For more information about these studies, see the references below.  Marker Gene sells several products for sensitive and specific staining of lacZ-positive cells and tissues (including: M0250; M0259; M0241; M0255; and M0257).

• Clarke, D. L. Johansson CB, Wilbertz J, Veress B, Nilsson E, Karlstrom H, Lendahl U, Frisen J., “Generalized potential of adult neural stem cells.” Science 288, 1660-1663 (2000).
• McKay, R., “Mammalian deconstruction for stem cell reconstruction” Nature Medicine (2000) 6( 7):747-748.
  
  

New Apoptosis Detection Kits. 

Apoptosis is a tightly controlled process by which cells undergo a series of changes including violent membrane depolarization and blebbing (called zeiosis), and fragmentation of DNA creating a vacuolar nucleus. I contrast to necrosis, apoptotic cells break into smaller pieces called apoptotic bodies that allow recycling of cellular components.  Several enzymes are involved in the cascade of events that initiate apoptosis.  Our new Magic Red^TM-based substrates and kits for detection of the important enzymes Caspase 3 and 7 (M0837, M0838) as well as Cathepsin B (M0839), K (M0841) and L (M0843) will soon be available from Marker Gene.  These kits provide the substrates, reagents, counterstains and detailed protocols for use in sensitive analysis of these important enzymes involved in programmed cell death (Apoptosis) and in a number of disease states including cancer, neurodegenerative diseases or congestive heart failure.  For more information about these kits, please see our new catalog, visit our Web site at www.markergene.com or email us at techservice@markergene.com .

Over 40 New Products and Kits in the New Catalog!

The 2003-2004 edition of the Marker Gene catalog is due from the printers in a few weeks.  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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