DNA profiling | Definition

Doc's CJ Glossary by Adam J. McKee
Course: Criminal Investigations

DNA profiling, or genetic fingerprinting, is a technique that identifies an individual based on their unique DNA signature.

Think of DNA as a unique barcode that’s different for every person. DNA profiling is like scanning this barcode to identify an individual. It involves analyzing particular regions in a person’s DNA. These regions vary significantly between individuals, making this a powerful tool for identification.

How DNA Profiling Works

This technique doesn’t look at a person’s entire DNA. That would be like reading a book to find a single word. Instead, scientists analyze specific sections of the DNA. These sections are called markers.

Markers are areas in the DNA that show the most variation between people. In a lab, scientists use a process called PCR, or Polymerase Chain Reaction, to make millions of copies of these markers. This process creates enough DNA material for them to work with.

The result is a series of numbers, like a genetic barcode. This series of numbers is unique to each person, representing their specific genetic traits.

Criminal Investigations

One of the main uses of this technology is in criminal investigations. Investigators collect DNA samples from a crime scene. This could be blood, saliva, or hair.

In the lab, scientists create a profile from the crime scene samples. They compare this with the profiles of suspects. If they find a match, it strongly suggests the suspect was at the crime scene.

It is widely regarded as a highly reliable technology. It can link a suspect to a crime scene or rule them out. This process helps to ensure that the right person is held accountable.

DNA Profiling Beyond Crime Scene

DNA profiling isn’t just for solving crimes. It’s also used in paternity testing. In these cases, scientists compare the child’s DNA profile with the alleged father’s profile. If half of the child’s DNA markers match the father’s, it confirms paternity.

DNA profiling is also used in immigration cases. Sometimes, families are separated, and they need to prove their relationship for reunification. In such cases, DNA profiles can provide the necessary proof.

DNA Sample Collection

DNA can be collected from a variety of sources. These can be blood, saliva, hair, or skin cells. Saliva is often the preferred source because collecting it is non-invasive. It’s as simple as swabbing the inside of a person’s cheek.

Once collected, the DNA sample is taken to the lab. There, scientists extract the DNA and create a profile. They then compare this profile to reference samples to check for a match.

Reliability of DNA Profiling

Because DNA is unique to each individual, it provides a highly accurate method of identification. This accuracy makes DNA profiling a trusted tool in forensic science and beyond.

To sum it up, DNA profiling is a powerful method for identifying individuals. By examining specific markers in a person’s DNA, scientists can create a unique genetic barcode. This profile can help solve crimes, confirm familial relationships, or even aid in immigration cases. DNA profiling is a remarkable testament to the power of genetics in our world.

[ Glossary ]

Last Modified: 05/16/2023

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