A DNA-Based Biological Sample Tracking Method

Abstract

Validity of data is inexorably linked to proper sample identification throughout the research process. Even low error rates in sample identification can have a significant, negative impact on study results. Unfortunately, most samples themselves are not tagged; instead, a label is placed on the container. The labels maybe illegibly printed, smudged, or fall off during storage. This can lead to misidentification of samples. GenVault has developed a novel backup system for labeling the biological samples themselves and not the container. For example, DNA samples are stored in a 384-well plate that contains Whatman FTA^® paper and a mixture of a five or more oligonucleotide sets differing in length by 10 base pairs. This combination of oligonucleotides is referred to as GenCode and can be co-eluted along with the DNA sample, providing a permanent sample identifier. These oligonucleotides and primer pairs have been "BLASTed" against human genomic DNA sequence to ensure that they are not complementary and do not produce nonspecific PCR products. By separating the amplified oligonucleotides via electrophoresis, the absence or presence of the individual oligonucleotides can be determined. Combinations of oligonucleotides can represent binary numbers. One is indicated by the presence of the amplified oligonucleotide product and zero by the absence of the oligonucleotide product. The specific binary number can be directly related to the individual plate barcode number and the corresponding sample identity. Six sets of five different oligonucleotides can represent as many as one billion unique codes, allowing precise identification of the original DNA samples.