But what methods are you using to quantify the quality of your samples before they’re used? How can you know if the sample has maintained its integrity and is 100% “now” what is was when it was first collected?
Some studies have shown that sample quality can be maintained long-term. For instance, back in 2007 researchers conducted sample handling and storage validation studies which justified the sample handling and storage procedures adopted in the UK Biobank project.
However, as an article in Nature points out, sample stability cannot be assumed. Indeed, some samples may change in unpredictable ways. From the article:
“One study showed that the concentration of two cancer biomarkers seemed to increase by around 15% from the time that the serum samples were collected and frozen to when they were thawed and measured again about 10 years later. In another experiment, designed to simulate long-term freezing, researchers examined how several cancer biomarkers changed in serum samples that were frozen and then thawed. Some protein biomarkers seemed to be stable for decades even with multiple freeze–thaw cycles. However, vascular endothelial growth factor — an extensively studied biomarker implicated in diabetes, arthritis and cancer — was so unstable that the authors recommended that it should never be measured in samples that have been frozen.”
As we’ve mentioned before on this blog, an ISO standard would help establish criteria for quality, agreed to by the majority of biobank stakeholders, and so help biobanks reduce business risks, improve efficiencies, ensure research integrity and enhance the credibility of their samples, data and the research results produced using them.
In the meantime, I’m curious about you handle quantification of the quality of the samples you work with. Please particpate in our Biobanking survey.