Not surprisingly, the challenge arose from UK Biobank, which has defined a protocol for the fractionation of whole blood. UK Biobank is in the process of collecting five blood samples each from 500,000 people to provide a resource for researchers to study correlations between disease, genes, and the environment.
Manually fractioning blood, Harding noted, is time consuming. “A single lab technician can fraction around 50 samples a day, which includes other operations like tube labeling and recapping. It’s easy to see that processing 3,500 samples per day would require a fairly large workforce. Automation was the obvious solution.”
The UK Biobank issued a request for proposals (RFP) knowing that there were no standard machines to fractionate blood according to its protocol available on the market. “Our team reviewed the RFP and not only was it clear that high throughputs were required at a level where our industrial approach would be a benefit,” Harding noted, “but it also seemed possible that our computer vision technology and expertise could be put to good use as well.”
Harding’s team took images of spun blood at a local university and processed them with the RTS Vision System. While it was clear that the RTS system could identify the two interfaces between the three layers of blood, there were many practical challenges to overcome to turn this concept into reliable automation. “These included the variability of blood samples and performing the whole protocol at a reduced temperature,” Harding explained. “So, we embarked on a collaboration with UK Biobank to solve the problem of identifying and separating all three layers in the blood in a reliable automated fashion.”
The combination of the Vision System with the company’s high-throughput automation went live in April 2007 and is now processing samples from over 300 participants a day, six days a week. From each participant, six tubes (five blood, one urine) are obtained, and four are processed on a fractionation system. “The Biobank processes 1,800 samples a day, operating with four technicians,” Harding noted.
Finally, Harding addressed the problems associated with automated sample storage. “Currently, -20ºC is the standard,” said Harding, “but we are in the process of researching and developing a -80ºC storage unit. Our solution solves key hurdles of temperature stability of the sample, frosting, and the price.”
Conventionally, storage of biological samples has been dominated by freezing and fixation techniques. “These techniques have major limitations such as lengthy preparation of samples with associated risks of sample deterioration, cost of maintenance at low temperature, and creation of artifacts due to invasive procedures,” noted David Wellis, Ph.D., president and CEO of GenVault (www.genvault.com).