Posted on 08/29/2009 12:49:30 PM PDT by neverdem
European scientists have developed a method to detect potential biological warfare agents in food.
Protein toxins are detected most effectively using immunological techniques, since antibodies bind to their targets with very high affinity. However, current methods for raising antibodies against toxins without causing animal poisoning are time consuming and labour intensive. Dorner and coworkers have used an alternative technique, immobilising the toxins on microbeads to reduce their toxicity, allowing the team to generate antibodies quickly in vivo.
|
Castor bean protein ricin inhibits protein synthesis in the body
© USDA-ARS
|
The researchers then modified a commercially available system to analyse complex food samples using the antibodies. In Luminex xMAP technology antibodies are covalently coupled to beads embedded with dyes that generate signals in response to different targets - in this case the toxins. Dorner explains: 'We further developed the Luminex xMAP technology to incorporate magnetic beads to allow us to analyse complex matrices.' The magnetic property means that the beads can be easily removed from food samples and can undergo automated washings. This makes toxin detection in foods possible where many other technologies have failed due to interference of sample components with binding agents or technical equipment.
Using the bead array, the researchers simultaneously detected trace amounts of five toxins, including ricin and botulinum neurotoxins, in food at lower concentrations than commercially available systems. Dorner says the technique has very good sensitivity. 'We are able to detect toxins down to a level of picograms per millilitre which, as far as I know, is superior to any limit published for other multiplex detection systems,' she says.
Phillipe Thullier from the Research Centre for Armed Forces' Health in La Tronche, France, is an expert in the field of immunological techniques for toxin detection and neutralisation. He comments: 'The sensitivities are quite unique and to a large extent are made possible by the beads. In the future,' he adds, 'we could see more of these nano objects in biology, used for several purposes.'
Dorner anticipates a possible commercial application for the technique. 'A further step would be introduction of a mobile device using the bead array,' she says, 'and a very nice use of the technique would be large scale screening of the food supply chain.'
Simultaneous quantification of five bacterial and plant toxins from complex matrices using a multiplexed fluorescent magnetic suspension assay
Diana Pauly, Sebastian Kirchner, Britta Stoermann, Tanja Schreiber, Stefan Kaulfuss, Rüdiger Schade, Reto Zbinden, Marc-André Avondet, Martin B. Dorner and Brigitte G. Dorner, Analyst, 2009
DOI: 10.1039/b911525k
David Russell is using chemistry in the fight against terrorism and disease. Joanne Thomson finds out how.
A new assay for a lethal toxin could help scientists develop better inhibitors of the poison
This fascinating book takes the reader on a journey of discovery into the world of dangerous organic poisons.
I hope they include poisonous mushrooms. Those are some vicious octopeptides.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.