When your client sends off a saliva sample or cheek swab for genetic testing, it can feel like it disappears into a system that they never see. Weeks later, a report appears with charts, percentages, and explanations, but very little sense of what actually happened in between.
At GeneMetrics, we believe that process should not be mysterious. A client does not need to be a molecular biologist to understand what is happening to their DNA, but they should be able to understand the steps clearly enough to trust the outcome.
So, let’s step behind the scenes and see how DNA processing actually works, using a method known as lifestyle sequencing or (GSLS) that focuses on genetic markers related to wellness, traits, and long-term health tendencies.
Step 1 > Sample Collection and Lab Intake
The process starts with a saliva sample or cheek swab that takes less than a minute to do. In simplest terms, a client uses a long cotton bud to swab the inside of their cheek, making sure they have not eaten or drunk anything for at least 30 minutes beforehand. This is to prevent their DNA results from claiming they are 30% coffee bean.
These samples collect something called epithelial cells- the soft tissue that can be felt on the inside of the cheek. Every single one of those cells contains a full copy of their DNA. To understand how amazing DNA is- if we unwound all the DNA in the human body- it would reach all the way to Pluto- a truly mindboggling amount of data.
“If you unwound all the DNA in your entire body- it would reach all the way to Pluto- a truly mindboggling amount of data.”
The cotton swab is then popped into a vial and posted to our CLIA-certified laboratory.
When the sample arrives at the laboratory, it is logged through its unique and anonymous barcode. From this point onward, it is tracked as a sample ID rather than a person. This separation supports both privacy and quality control — a core principle at GeneMetrics.
At this stage, nothing is analysed. The sample is simply biological material waiting to be processed.
Step 2 > DNA Extraction: Getting to the Genetic Material
Next, technicians extract DNA from the collected cells.
They add chemical lysis buffers to the DNA sample that breaks open cell membranes and then purifies the DNA by removing proteins and other cellular debris. Many modern labs use magnetic silica bead–based kits to do this.
Once extracted, the DNA is checked for:
- quantity (“is there enough DNA?”)
- purity (“is it free from contaminants?”)
If the DNA does not meet minimum thresholds, the process stops here. This is an important safeguard: poor input DNA almost always leads to poor downstream results.
Step 3 > Making DNA Readable by Machines
DNA in its natural form is very long and continuous. Unlike us humans, DNA sequencing machines cannot read it like a book. Instead, the DNA is prepared into a format that machines can handle.
This stage, called library preparation, typically involves:
- turning the DNA strand into shorter pieces (often a few hundred base pairs long)
- attaching adapter sequences to each piece
- and to speed it up, adding short index barcodes so multiple samples can be run together
Commercial kits from suppliers such as Illumina are commonly used here, and quality checks ensure the fragment sizes are within tight ranges.
The result is a DNA library that is ready to be read.
Step 4 > Sequencing: Reading the Genetic Code
Next, the DNA pieces are loaded onto sequencing machines that can read the code written within. Depending on the test, this might include platforms such as Illumina MiSeq, NextSeq, or NovaSeq.
These machines use a method called sequencing by synthesis. In simple terms:
- DNA pieces bind to a flow cell
- fluorescently labelled bases (A, T, C, G) are added one cycle at a time
- cameras capture the signal as each base is incorporated
This process happens millions to billions of times in parallel. The output is raw sequencing data that contains short DNA reads and quality scores that show how certain we are that the machine has read the code correctly.
At this point, the data is still unreadable to humans- if you looked at a raw DNA file, it would make no sense.
Step 5 > Bioinformatics: Turning DNA into plain English
GeneMetrics has built specialised software and algorithms that can read those large raw DNA files. In simple terms, we take those short DNA reads and compare them to a reference human genome using two versions, either GRCh37 or GRCh38.
This is often misunderstood- we do not compare the DNA to a “perfect” DNA sample or even a “normal” one. It is simply a comparison that shows which base pairs of A T C or G are possible at that specific position on the genome.
This step produces a list of genetic variants, such as single nucleotide polymorphisms (SNPs) and small insertions or deletions in your DNA code.
Coverage depth and consistency checks help ensure that the variants reported are reliable.
Step 6 > DNA Reports: Where Science Meets Judgement
Finding variants is not the same thing as understanding them.
Most traits and health-related risks are influenced by many variants, each with a small effect, and by non-genetic factors such as environment and sometimes pure chance.
Our reports are designed to show your client’s DNA results by taking into account:
- How does this result compare to population averages?
- How strong is the supporting evidence?
- Is this something worth paying attention to, or background noise?
At GeneMetrics, interpretation is intentionally conservative. Our reports are framed as tendencies and probabilities, not diagnoses or predictions. Strong evidence is distinguished clearly from emerging or uncertain findings.
Step 7 > Privacy After Analysis
An important part of this workflow is what happens after insights are generated.
At GeneMetrics, genetic data is processed to create results and then removed. There is no long-term database of individual genomes and no stored dataset from which a person’s DNA could later be reconstructed.
What remains are interpretations and explanations, not a permanent genetic blueprint. This reduces risk by design as we understand how important medical data privacy is.
In closing….
And there you have it: behind every genetic report is an unbroken chain of lab chemistry, sequencing machines, statistical models, and human judgement. The goal is not to extract every possible signal, but give the best possible understanding of future health tendencies
When people can see the process clearly, they are far less likely to misuse the results.