Biobanking on the future

The UK Biobank hopes to collect biological samples from 500,000 people over the next four years to help determine the causes of many fatal conditions. To do so biological samples, such as blood, urine or tissues need to be collected and the accurate archiving of these is of the utmost importance if the data is to have any relevance. Pharmaceutical companies are more commonly storing samples from patients who are involved with clinical trials, as this can help find genetic reasons for specific reactions to drugs. AstraZeneca recently published an article in The Pharmacogenomics Journal​​ (15 May 2007, p1-10) that describes a retrospective case-control pharmacogenetic study to determine the cause of an adverse event (AE) associated with taking the now-withdrawn Exanta (ximelagatran). This study would not have been able to determine the genetic cause of the AE if AstraZeneca had not had access to biological samples from those patients taking the drug. According to Erdal Demir of Micronic, a biological sample can cost €1000 to store and therefore it is imperative that the sample is stored in a safe and fully traceable manner. Once the sample integrity is ensured by storage in a tube that will not leach plastic into the sample the next problem is ensuring that the sample can be correctly identified - even after being stored for several decades. "Imagine how valuable a sample is after it has been stored for 20 years, researchers cannot risk such valuable assets with inferior storage or labelling systems,"​ said Demir. Sample tubes need to be made from solvent resistant materials such as glass or polypropylene and the codes need to be solvent resistant to ensures that the code can not get washed off even if the sample vial is dropped in solvent. The type of material used for storing samples is important with black tubes ideal for storing light sensitive samples in and glass tubes useful for storing bioactive samples that could react with plastic tubes. To ensure no stray biological matter gets into the tubes sample tubes need to be manufactured in class 7 clean room facilities. Micronic have developed a system that involves incorporating a laser etched 2D code to the bottom of a sample tube that ensures the code does not fade or peel off even when subjected to repeated handling and freeze-thaw cycles. Samples can also be labelled with RFID (radio frequency identification) tags that allow fast electronic sample identification although this approach can be too expensive for the larger state-run biobanks. Demir explained that it was advantageous to store samples in individual tubes rather than in multi-well plates that contain multiple samples as it helps preserve samples that are not being studied in the plates. This is particularly important as biological samples are often stored at -80ºC and each freeze-thaw cycle will degrade the sample a little bit. With the largest biobanks containing upwards of 14m samples, minimising the footprint of a rack of sample tubes is an issue, and Demir explained that Micronic's racks are all produced according to the internationally recognised Society of Biomolecular Screening (SBS) standard footprint. With biobanks and pharmaceutical companies storing such huge numbers of samples ensuring the racks are compatible with automated sample handling systems is a necessity and Micronic's Sure-Shot contoured rack top increases productivity by allowing easier tube insertion and removal. Micronic have also designed their racks with a novel airflow design that aids rapid freeze-thaw cycles.