Home > Forensics > Performing DNA Typing

Performing DNA Typing

By: Ian Murnaghan BSc (hons), MSc - Updated: 7 Mar 2014 | comments*Discuss
 
Dna Typing Concept Techniques Marker

DNA typing is an important aspect of many fields and applications such as forensic science, medicine and paternity disputes. It goes by many names, including DNA fingerprinting, profiling or testing. The approach is not a singular one, which means that there are numerous techniques used to perform DNA typing. Research is continuously evolving and techniques are regularly refined or replaced by newer, more sophisticated ways to perform DNA typing. While you may be interested to read an overview on the different ways to perform DNA typing or even read in-depth on each technique, it can be helpful to simply get a basic sense of why we even perform DNA typing and how it is so important to a broad range of fields.

Differences Between People

At an extremely simplistic level, DNA typing takes advantage of the fact that we are all different. Your DNA is a unique fingerprint and is not shared with anyone else, with the exception of identical twins and clones. Still, if you look at it in another light, all humans share much of the same DNA. Yet, given how many bases are in DNA, there are still approximately three million bases that are different from one person to another. In fact, it is fascinating to consider that it is roughly one-tenth of just one percent of DNA that is different. These differences are exploited in the laboratory to create a DNA profile of a person. The sample may be taken from a person's hair, blood, body tissue or many other locations. If the DNA typing is meant for a criminal investigation, then the sample would likely be collected at a crime scene and then assessed for certain DNA markers.

Understanding DNA Markers

DNA markers are an important aspect of DNA typing. A scientist or technician will identify DNA markers from a sample by using something called DNA probes, which find a complementary DNA sequence within the sample and then bind to it. A set of probes that will bind to a sequence of DNA will produce a special, unique pattern for a person. By comparing DNA profiles, scientists can then create data that may be useful for applications such as a criminal case. A scientist might check to see if the DNA profile is a match between a suspect in a crime and evidence found at the scene of the crime.

Assessing a Match

It is important to keep in mind that one marker is not considered enough to match up evidence. Of the thirteen regions that differ within humans, one or two markers matching is not considered a strong match but five would be considered reasonably strong and more likely to indicate that the DNA typing is indicative of the same person. It is, however, still a balancing act to assess how strong the DNA typing is with regards to a match. Some scientists cite that DNA typing is more advanced and better than an eyewitness statement.

DNA typing may be a concept with several names and even more techniques, but it will continue to operate on a simple premise, which is that humans are different and these differences can be measured and compared to provide important information.

You might also like...
Share Your Story, Join the Discussion or Seek Advice..
I like the topic of DNA typing.
santi - 7-Apr-11 @ 9:19 PM
Share Your Story, Join the Discussion or Seek Advice...
Title:
(never shown)
Firstname:
(never shown)
Surname:
(never shown)
Email:
(never shown)
Nickname:
(shown)
Comment:
Validate:
Enter word:
Topics
Latest Comments
  • Laverne
    Re: Using DNA and for Immigration Purposes
    Hi..i am a USC. I petition for my stepchildren who are in Jamaica and the petition has been approved. I have since…
    9 August 2019
  • Mhay
    Re: DNA Test after Death
    I need some answer...my son died 24 years ago, August 6,1995, he was born July 29,1995, I just have doubts in my mind, as Fabella Hospital in…
    30 July 2019
  • mich
    Re: DNA Test after Death
    I would like to know if an old baseball cap would have my father's dna. My dad passed away in 2010.
    30 July 2019
  • Gurl
    Re: DNA Test after Death
    My grandmother passed and I want to do a DNA-genealogical test. I did the 23 and me test and it was revealed I am 47percent Native American.…
    26 July 2019
  • fredab
    Re: DNA Test after Death
    hi , my son passed away ,17 years ago in2001 and he had a baby on the way ,she was born in june 2002 , she is 17 years old now ,but we had…
    27 June 2019
  • Richie
    Re: DNA Test after Death
    My sister was adopted by my Aunty at a very young age. We met for the first time when I was 35 years old and she was 45 years. We were in…
    25 June 2019
  • spearmannbails
    Re: DNA and Criminology
    no. deoxyribonucleic acid is to be for biology, and biology only.
    24 June 2019
  • Casey
    Re: DNA Testing for Pets
    Hi, I was wondering if there was any chance you could do a DNA test on my dogs ashes, for a long time we suspected he wasnt full Siberian…
    18 June 2019
  • Vee
    Re: DNA Test after Death
    Can I text my 4 month old baby ashes, there is pieces of her bone,
    12 June 2019
  • Cami
    Re: DNA Viruses
    Are you able to give me an explanation of how prescribed medicines may cause DNA mutations? As far as I know they can bind the DNA strands…
    11 June 2019