News From The American Chemical Society Feb. 27, 2008

A nano-sensor for better detection of Mad Cow Disease agent



In an advance in food safety, researchers in New York are reporting development of a nano-sized sensor that detects record low levels of the deadly prion proteins that cause Mad Cow Disease and other so-called prion diseases. The sensor, which detects binding of prion proteins by detecting frequency changes of a micromechanical oscillator, could lead to a reliable blood test for prion diseases in both animals and humans, the researchers say. Their study is scheduled for the April 1 issue of ACS' Analytical Chemistry, a semi-monthly journal.



Prions are infectious proteins that can cause deadly nerve-damaging diseases such as Mad Cow Disease in cattle, scrapie in sheep, and a human form of Mad Cow Disease called variant Creutzfeldt-Jakob Disease. Conventional tests are designed to detect the proteins only upon autopsy and the tests are time-consuming and unreliable.



In the new study, Harold G. Craighead and colleagues describe a high-tech, nano-sized device called a nanomechanical resonator array. The device includes a silicon sensor, which resembles a tiny tuning fork, that changes vibrational resonant frequency when prions bind. Its vibration patterns are then measured by a special detector. In experimental trials, the sensor detected prions at concentrations as low as 2 nanograms per milliliter, the smallest levels measured to date, the researchers say. - MTS



"Prion Protein Detection Using Nanomechanical Resonator Arrays and Secondary Mass Labeling"



CONTACT:

Harold G. Craighead, Ph.D.

Cornell University

Ithaca, New York 14853



The incredible, hypoallergenic egg: New process to help egg-allergy sufferers




People who suffer from egg allergies may soon be able to have their quiche and eat it too. Chemists in Germany and Switzerland report development of a new process that greatly reduces allergens in eggs and may lead to safer, more specialized food products for individuals with egg allergies. Their study is scheduled for the March 12 issue of ACS' Journal of Agricultural and Food Chemistry, a bi-weekly publication.



Although unusual in adults, egg allergies are among the leading food allergies in infants and children. These allergies can cause severe stomach aches, and rashes. In extremely rare cases, death may occur. As a result, physicians advise those with egg allergies to avoid eggs or egg-based products. Some researchers have tried to reduce allergens in eggs, especially the pasteurized egg product (consisting of shelled eggs) widely used in the food industry. Until now, however, those efforts have been largely unsuccessful.



In the new study, Angelika Paschke and colleagues describe their process, which exposes raw eggs to a combination of high heat and enzymes to break down their main allergens. The researchers then tested their reduced-allergen egg against blood serum collected from people with egg allergies. The modified egg product was 100 times less allergenic than raw egg, the scientists say. It does not significantly affect flavor and texture when used in various products, they add. - MTS



"In Vitro Determination of the Allergenic Potential of Technologically Altered Hen's Egg"



CONTACT:

Angelika Paschke, Ph.D.

University of Hamburg

Hamburg, Germany







The American Chemical Society - the world's largest scientific society - is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.



Source: Michael Woods


American Chemical Society