At the heart of the UK Biobank project is a purpose-built archive facility – a giant freezer for storing millions of blood and urine samples over many years.

The £4.5 million high-tech store is one of the biggest resources of its kind anywhere in the world. It will keep the 10 million separate samples from the 500,000 participants at -80C for the next several decades. The facility was a runner-up for the prestigious Royal Academy of Engineering MacRobert Award in 2008.

UK Biobank has drawn together specialist knowledge and systems from the UK and other parts of the world to ensure that participant samples can be stored safely and efficiently for many years. The system can work day and night to store – and now, more importantly – to retrieve up to 4,000 samples in 24 hours, more quickly and accurately than can be done by hand. These samples of blood, urine and saliva can then be linked to health information collected at assessment, and to a range of health conditions, making this a hugely important resource for research.

Dr Tim Peakman, UK Biobank Executive Director, said: “As well as its sheer size, this state-of-the-art facility is one of the very real achievements of the project – allowing samples to be stored carefully and retrieved rapidly for the lifetime of the project.”

Each sample of blood is stored in a number of tubes, called aliquots. They are identified by a unique bar code, so that the individual ‘donor’ remains anonymous. A frozen, frost-free storage environment is crucial if the bar codes are to be read and successfully retrieved in years to come.

“Frosting is one of our biggest concerns,” says Dr Peakman. The solution is to ensure that the air circulating within the freezer is as dry as possible – as low as 2 parts per million of water vapour (compared with 10,000 to 12,000 outside on a relatively humid summer’s day). This means that frost cannot form to disable the robotics and make the bar codes on the tubes illegible. Water vapour is removed from compressed air by twin air dryers at the back of the store before feeding it into the system.

Samples are stacked in -80C trays along a 27 metre central ‘corridor’ that is kept at -20C. A robotics system controls the archival and retrieval processes. The system allows for precision storage that could not be achieved by hand; it can put away 8,500 samples in an hour. The freezer is 7 metres wide and 6 metres high. Its full weight is 20 tonnes.

About 100,000 litres of dry air and 5,000 litres of liquid nitrogen are fed through the system each day, making UK Biobank one of the biggest consumers of liquid nitrogen in the country.

The central robotic arm in the freezer, pictured right, can travel at a speed of 2 metres a second, and accelerate at 1.5m/per second/per second. Meanwhile, processing robots in the UK Biobank laboratory do the work of 40 technicians working an 8-hour day.

The archive facility was officially opened by HRH The Princess Royal in 2009. The facility was designed and built with the help of Royston-based company The Automation Partnership.