What is DNA?
DNA is often referred to as the “building block of life”. This is because it stores, in coded form, all the genetic information needed to create a living being.Discovering the structure of this amazing molecule was one of the most important scientific breakthroughs of the 20th century. The first description of DNA structure was published in 1953 by James Watson and Francis Crick. Their research would earn them the 1962 Nobel Prize in Medicine and Physiology.
Our Process
In our testing labs in Maryland and at the University of London we extract the DNA from your swab. This involves breaking the cells to release tiny quantities of DNA. Once this is separated from the rest of the cell it’s washed to ensure there are no contaminants. The DNA is then kept in tubes at a temperature of -20°C.
Your genome, your complete set of genes, is extremely large. There are 3 billion bases, or chemical components, grouped into 46 chromosomes. We could analyze directly from this raw DNA but, to make the process much more efficient, we concentrate on a small region of around just 200-400 bases. We then obtain the DNA sequence by employing a technique known as ‘polymerase chain reaction’, or PCR for short. PCR is at the core of much molecular biological work and its inventor, Dr. Cary Mullis, received the Nobel Prize in recognition of this. PCR allows a scientist to ‘zoom in’ on a short, specific stretch of DNA and then make copies of this region.
GeoGene takes a small quantity of your DNA and adds it to a tube with some chemicals that will create a PCR reaction. These include some small pieces of DNA called primers, and some copies of the sequences as well as some other key nucleotides and enzymes. This mix is loaded onto a machine where it is alternately heated and cooled 20-40 times. This helps trigger the reaction and allows multiple copies of the relevant sequence to be completed. By the time the process has been completed, the tube will contain millions of copies of the stretch of DNA we are interested in.
The next step in the process is to determine the sequence of this amplified region. GeoGene does this using a technique known as automated fluorescent DNA sequencing, which, we admit is a bit of a mouthful.
GeoGene analyses your DNA sequence using computer software to identify the exact base positions that hold the key to your Y chromosome’s demographic history. By deducing what sites you are either ‘derived’ or ‘ancestral’ for, we can identify how you fit into the phylogenetic tree of worldwide Homo sapiens Y chromosomes. Or, in short, where your ancestors came from!
