Massively parallel sequencing of gene panels or even whole exome sequencing is becoming more and more common in the majority of the diagnostic and research labs world wide. Although quality checking of samples (e.g. yield, level of degradation, ...) is routinely done, validating sample identity prior to or post sequencing is often overlooked. Nevertheless, it estimated that sample swaps occur in 0.1 to 1% of cases. In a research setting, this can have a major effect on the interpretation of results and downstream applications, while errorneous results can be reported to patients in a diagnostic context - potentially affecting treatment options. That is why it is always best to assess the identity of your samples (especially prior to sequencing) using an independent SNP based genotyping method. The genomic features usually used in such method are series of SNPs having a minor allele frequencies appromixating 0.5 (or 50% allele frequency). By assessing the genotype status of all these SNPs in your sample at the beginning and end of your workflow, you can ensure no sample swaps have occured.
We have developed two sample tracking panels, one 30 SNP panel suited for high-quality DNA samples and a second 44 SNP panel for degraded samples such as FFPE or plasma cell-free DNA samples. More information on these panels can be found in this presentation or this brochure. If you want more information or wish to test one of these panels, please contact us using the contact form.