Half of all athletes taking part in the London Olympics will be tested for drugs in what is being billed as the biggest anti-doping operation in the history of the Games.
A team of 150 scientists will take more than 6,000 samples between now and the end of the Paralympic Games on September 9 in a bid to ensure the Games are not tainted by disqualifications and scandals like those which have happened in the past.
The London 2012 anti-doping laboratory, operated by GlaxoSmithKline (GSK), Locog and King's College London, will be in operation 24 hours a day, seven days a week.
Among those tested will be every competitor who steps on to the medal-winners' podium.
UK athletes Phillips Idowu, Beth Tweddle, David Weir, Graham Edmunds and Marlon Devonish are to appear in a television and billboard advertising campaign run by GSK to highlight the importance of the anti-doping operation and the science behind it.
Sprinter Devonish, who won Olympic gold in the 4x100m relay at the 2004 Athens Games, said: "Winning an Olympic medal is the best feeling in the world and as an athlete it's so important to know that anyone who stands on the podium has got there through their own hard work and dedication, not by doping."
Testing will take place at the London 2012 lab in Harlow, Essex, with the scientists led by Professor David Cowan from the Drug Control Centre at King's College London.
More than 1,000 people will staff the lab, with up to 400 samples tested every day for more than 240 prohibited substances.
Drugs have been in the spotlight after sprinter Dwain Chambers and cyclist David Millar had their British Olympic Association lifetime bans for drug taking overturned by the Court of Arbitration for Sport (CAS) and the World Anti-Doping Agency (WADA). Both will compete at the London Games.
Double gold medal-winning Paralympic swimmer Graham Edmunds, who was part of the winning 4x100m freestyle relay teams in Athens and Beijing, will appear on a giant advert for the doping programme on the side of GSK's headquarters in Brentford, west London. He said: "I'm confident that everything possible is being done to catch drug cheats at London 2012 and that makes these Games really special."