What is the science behind DNA tests?
What is the science behind DNA tests?
Every person’s DNA (deoxyribonucleic acid) is unique (excepting identical twins).
There are three types of DNA testing: parental, forensic and genetic.
All the cells in the body contain exactly the same DNA and samples could be taken from any part of the body (blood and bodily fluids, hair, skin, or other tissues).
The first step is to collect and isolate DNA.
Second, the DNA is replicated using a technique called PCR (polymerase chain reaction). By doing so, the DNA becomes easier to analyse.
The DNA is then split, using Agarose Gel. The process is called elecreophoresis and it helps separate fragments of DNA according to their structure and dimensions, helping researchers visualize the fragments (chunks). This is how the DNA fingerprint is determined.
A forensic scientist might have to compare the DNA found at a crime scene with the DNA of a potential suspect.
In case of paternity tests, the DNA of both father and child will be collected and compared. The similarity between a true father and child should be above 75%.