The storm that broke in the press following the discovery of horse DNA in burgers on sale in Britain has rocked the supermarket giants and a sparked widespread concern about all aspects of food safety

But in some respects, the surprise is that people are surprised. The risk of adulteration of food either by unscrupulous traders or lackadaisical processors is something to which standards agencies - not just in the UK but around the world - must stay continually alert.

It is generally accepted that dubious practices in the meat processing industry are far from a new phenomenon. A director of environmental health, writing recently in the Times, recalled a two-year investigation in 1980-81 into the sale of horse, kangaroo, donkey, buffalo and knacker meat as beef in burgers, which led to the staining of unfit meat.

And food purity Acts were passed in the US as far back as 1906 following allegations about the meat industry in Upton Sinclair's novel, The Jungle. Even further back, there is well-founded speculation that the men of the ill-fated Franklin Expedition to the Arctic died horrible and puzzling deaths as a result of botulism in their canned food.

What is new in the horse burger story is the increasingly sophisticated methods that scientists are bringing to bear in the ways they can pinpoint and track down infinitesimally small particles in samples of food.

While the ability to analyse and identify different types of meat is not new, the methods which revealed the DNA in the Irish burgers have only really been perfected over the past 30 years.

Polymerase chain reaction, or PCR, was developed by Nobel Prize winner Kary Mullis as a biochemical technology to amplify a single piece of DNA to generate millions of copies of a particular DNA sequence. The importance of the DNA is that, generally, it remains until the end of the food production chain, surviving the heat and the chemical elements within that process.

Within the meat production process in the slaughterhouse, from minced meat and processed meat up to meat containing feed, the species identification of minced and processed meat might not always be clear.

This poses a risk of product falsification meaning that meat from a species of lower value might be declared as meat from animals of higher value. This risk is higher in meat mixtures, for instance ground beef and its products. Using real-time PCR, different animal species can be identified. It also enables a highly specific identification of the animal species in the presence of meat from other species.

R-Biopharm Rhône offers a PCR service for the qualitative identification of animal species such as horse. The service offers a rapid turnaround from receipt of the sample and also an extremely sensitive detection limit depending on matrix and DNA preparation.

PCR is just one of the food safety services R-Biopharm Rhône offers. One of its main businesses in its Scottish operation, in the West of Scotland Science Park in Glasgow, is making mycotoxin kits, which test for toxins created by moulds.

R-Biopharm Rhône's biggest selling product is immunoaffinity columns, of which it made 800,000 last year. These columns use antibodies to bind and measure elements in samples and operate at astonishing levels of sensitivity.

Its test kits detect parts per billion and work is going on towards parts per trillion. To put this in perspective, identifying seven parts per billion is akin to picking out seven particular people from the entire population of the world.

The accuracy is vital, since the toxins the kits are detecting can have a devastating impact on the human body. Ochratoxin, found in cereals, dried fruit, coffee, wine and spices, causes kidney cancer. Aflatoxin, one of the most virulent toxins, causes liver cancer. Fumonisin, derived from a common grain mould, causes throat cancer.

R-Biopharm Rhône supplies both to food companies which have their own diagnostic laboratories and to private labs serving the food and agriculture industries. It also sells to public sector labs which are engaged in food testing as part of the government's statutory duty to ensure food safety.

For further information, contact Simon Bevis, managing director, R-Biopharm Rhône Ltd., Block 10, Todd Campus, West of Scotland Science Park, Acre Road, Glasgow, Scotland G20 0XA. Tel: +44 (0) 141 945 2924. Fax: +44 (0) 141 945 2925. Email: info@r-biopharmrhone.com. www.r-biopharmrhone.com