Biomedical research requires the use of primary samples that are derived directly from individuals affected by disease. The use of these primary research materials means that the health information connected to a person who donates a sample is tied up with the description of the sample itself. It’s critical, therefore, for biobanks to decouple this useful research material from a donor’s private information, a process known as de-identification. This protection of sample donors’ personal and identifiable information is paramount to preserving donor anonymity.
To accomplish this, repositories typically either de-identify incoming samples immediately upon receipt or receive samples that are de-identified before arrival. However, biobanks need to maintain definitive authentication of biological samples for quality control. This can be done via a genetic assay to generate a profile for each sample by analyzing the presence and size of repetitive regions in the genome, known as microsatellite markers (MSATs). This approach is an established and effective way to authenticate biobank samples.
In rare cases, a standard six-marker assay is not enough, and additional markers are needed for sample authentication. Interest in biospecimen profiling is not unique to biobanks, as government and law enforcement agencies rely on similar assays in forensic analyses, resulting in a database of MSAT profiles of DNA samples collected from crime scenes, known as the Combined DNA Index System (CODIS).
In the interest of maintaining internal sample authentication without the use of forensic markers, Coriell scientists developed a new, supplementary MSAT assay that does not rely on the MSAT markers used by law enforcement. Their work was published online in the journal Biobanking and Biopreservation this month (PMID: 34468209).
“Sample authentication is critical to biobanking, but it should be done in a way that protects those who donate samples.” said Laura Scheinfeldt, PhD, Director of Repository Science and corresponding author on the paper.
Using samples from the National Institute of General Medicine Sciences (NIGMS) Human Genetic Cell Repository and the National Institute on Neurological Disorders and Stroke (NINDS) Human Genetics Resource Center, both housed at Coriell, the paper’s authors developed and validated this assay to target MSATs not used by CODIS that could serve as new markers for sample authentication. Collaboration with members of the Scientific Advisory Committee of the NIGMS Human Genetic Cell Repository helped to identify promising markers.
The authors went on to demonstrate that the new assay reliably differentiates samples from both unrelated and related individuals.
This new assay is a method of sample authentication that offers added protection to individuals who contribute samples to biobanks, as the genetic profile it generates is categorically different than one used by law enforcement, so that the focus can remain on the original intention of the sample donation—to advance biomedical research.
