-
December 16, 2009
Latest News

Topics Covered
Latest News
October 28, 2011
Speedy Homemade-Explosive Detector
Forensic Chemistry: A new method could increase the number of explosives detected by airport screeners.
Solar Panel Makers Cry Foul
Trade: U.S. companies complain of market dumping by China.
Novartis To Cut 2,000 Jobs
Layoffs follow similar moves by Amgen, AstraZeneca.
Nations Break Impasse On Waste
Environment: Ban to halt export of hazardous waste to developing world.
New Leader For Lawrence Livermore
Penrose (Parney) Albright will direct DOE national lab.
Hair Reveals Source Of People's Exposure To Mercury
Toxic Exposure: Mercury isotopes in human hair illuminate dietary and industrial sources.
Why The Long Fat?
Cancer Biochemistry: Mass spectrometry follows the metabolism of very long fatty acids in cancer cells.
When it comes to glass microscope slides as substrates for protein microarrays, older is better. In general, microscope slides bought before 2008 make better microarray substrates than do newer ones, according to Chris R. Taitt and coworkers at the Naval Research Laboratory (NRL) in Washington, D.C. (Anal. Chem., DOI: 10.1021/ac902324r). The finding is a cautionary tale for researchers who use such microarrays as biosensors to detect proteins.
Earlier this year, Taitt and coworkers found that they were suddenly having problems using well-established silane chemistry to attach proteins to microscope slide surfaces. The problems resulted in biosensors with poor sensitivity. "An awful lot of people use this silane chemistry, whether they’re just modifying the surface to make it more or less hydrophilic or hydrophobic or immobilizing biomolecules for biosensors," Taitt says.
After experiments by Stella H. North fingered the slides as the culprits, Taitt called in colleagues Scott G. Walton and Evgeniya H. Lock from the Plasma Physics Division at NRL to characterize the slides. Using X-ray photoelectron spectroscopy and atomic force microscopy, they found that most microscope slides purchased before 2008 contained more magnesium and had rougher surfaces than newer slides. Taitt and her collaborators are still trying to figure out how low magnesium content and smoother surfaces lead to poor protein immobilization. They saw these differences between high-magnesium and low-magnesium slides in all the brands they tested.
Thermo Fisher Scientific, manufacturer of several of the slides tested, says it hasn't received reports from its customers of performance differences. "The production process used by Thermo Fisher for manufacturing glass slides has not changed since 1935," a company spokesperson says.
"Who would have guessed that both the surface chemistry and surface roughness of microscope slides sold all over the country have changed," says Frances Ligler, another NRL scientist who works with biosensors but was not involved in this research. "This paper reminds scientists wondering why their analytical data is not as good as that obtained by their predecessors to confirm the quality of even the simplest of their starting materials."
- Chemical & Engineering News
- ISSN 0009-2347
- Copyright © 2011 American Chemical Society
Services & Tools
ACS Resources
ACS Careers
ACS is the leading employment source for recruiting scientific professionals. ACS Careers and C&EN Classifieds provide employers direct access to scientific talent both in print and online. Jobseekers | Employers
» Join ACS
Join more than 161,000 professionals in the chemical sciences world-wide, as a member of the American Chemical Society.
» Join Now!