The Life of Your Sample

Kit Mailed and Received

When the sample arrives in the laboratory it is first given a unique identification number and entered into our laboratory’s information management system, which directs and monitors its progress through the lab. Once logged, the sample enters into the DNA isolation stage. As a reminder, it takes six to eight weeks to fully process your DNA from the time we receive your sample.

DNA Isolation and Analysis

In order to remove the DNA, the samples are incubated overnight in a protein-cutting enzyme. During this step, the cheek and saliva cells are dissolved, and the DNA is released into a solution. The next day each individual DNA solution is transferred by the “extraction robot,” to a new tube which contains specially coated beads that bind to the DNA when in the presence of certain chemicals. The beads (and the DNA) are then collected with magnetic probes and sent through a series of chemical washes, like a car moving through a car wash, before being dropped in to a storage buffer, where the beads release the DNA. Your DNA sample is then transferred to a tube and stored in a computerized freezer that records their exact position in each storage plate, and on the exact freezer shelf for future reference. It is now your unique DNA sample.

Participants like you who contributed your results to science, have helped us improve our understanding of the human genome so that we can now analyze at a more detailed level than when the project first began. As a result, the analysis stage differs between versions of the Genographic Participation Kit.

Geno 1.0 (first phase) participants: Certain chemicals are added to the samples to amplify and make billions of copies of the targeted regions of the DNA. This process is done using a technique called polymerase chain reaction (PCR). PCR produces short sequences of DNA, which can then be read like sentences in a book.

Geno 2.0 (swab kit): Samples are analyzed using a custom genotyping chip, which contains thousands of microscopic DNA probes attached to a solid surface. Each of these probes represents one position where there is the possibility of a difference in DNA sequence between individuals (known as a single nucleotide polymorphism, or SNP). This fully automated process uses a robotic liquid-handling system for efficient, error-free analysis.

Geno 2.0 (saliva): We use Next Generation Sequencing, or NGS.  In NGS, vast numbers of short reads are sequenced in a single stroke. First the input sample is cleaved into short sections. Then Polymerase Chain Reaction (PCR) is carried out to amplify each read, creating spots with many copies of the same read. Then these spots are heated and separated into single strands to be read, or sequenced on a slide. The slide is flooded with DNA polymerase enzymes and nucleotides, which are fluorescently labelled with four different colors corresponding to each base on the DNA (A, C, T, or G). They also have a reaction terminator, so that only one base can be added at a time. Once all of the fluorescent bases are added, the sequence can be read.

The data generated from these processes are then read by highly specialized software that analyzes the thousands of results returned for each sample. Once the analysis is complete, your results will go through a quality control process before being interpreted and uploaded for you to see.

Quality Control and Interpretation of Results

Quality control is an important step that ensures your results are correct. During this stage, a member of the laboratory team reviews the data for accuracy and checks for potential issues with DNA quality. Any samples with problems are flagged and rerun through the entire process.

Our team then compares your software-generated results to those of thousands of other participants and reference individuals to determine both your haplogroup (branch of the family tree) and your regional affiliation. Once your results have been interpreted and verified, they are uploaded for you to see. Have an additional question about Genographic testing or results? Visit our FAQ page.