Difference Between DNA Profiling and DNA Sequencing

The key difference between DNA profiling and DNA sequencing is that DNA profiling is a method used to identify an individual from a sample by looking at the unique patterns in the DNA, while DNA sequencing is a method used to determine the sequence of nucleotides in a piece of DNA of an individual.

Technologies like DNA profiling and DNA sequencing are very helpful to determine the inheritance pattern in a population. Though DNA profiling and DNA sequencing include some of the same techniques, the ultimate objective of each is different. Therefore, DNA profiling shows the genetic makeup of an individual. In contrast, DNA sequencing determines the genome and proteins an individual encodes.

CONTENTS

1. Overview and Key Difference
2. What is DNA Profiling 
3. What is DNA Sequencing
4. Similarities – DNA Profiling and DNA Sequencing
5. DNA Profiling vs DNA Sequencing in Tabular Form
6. Summary – DNA Profiling vs DNA Sequencing

What is DNA Profiling?

DNA profiling is a method used to identify an individual from a sample by looking at the unique patterns in the DNA. This technique was first discovered in 1984 by professor Sir Alec Jeffreys. DNA profiling detects lots of minisatellites in the genome to produce a pattern unique to an individual. This is called a DNA fingerprint. The probability of having the same DNA fingerprint between two people is very rare. Therefore, just like an actual fingerprint, the DNA fingerprint is unique to a person. DNA profiling usually involves the sampling of DNA and comparing it with a sample found at a crime scene.

In DNA profiling, first, DNA is extracted from human material. Then the restriction enzymes are used to cut the DNA. Next, the resultant pieces of DNA sizes are separated using gel electrophoresis. Once the DNA pieces are sorted out in the gel, they will transfer to a nylon membrane to produce single strands of DNA. The nylon membrane is incubated with radioactive probes. The probes are minisatellites. They only attach to pieces of DNA that are complementary. Finally, minisatellites in the sample DNA the probes attach can be visualized using X ray films. Moreover, this DNA pattern is a DNA fingerprint that is unique to an individual.

What is DNA Sequencing?

DNA sequencing is a method used to determine the sequence of nucleotides in a piece of DNA of an individual. It is also known as determining the order of nucleotides in DNA. The advent of various DNA sequencing methods has enormously accelerated biological and medical research. It applies to many fields such as medical diagnosis, biotechnology, forensic biology, virology, and bioinformatics. By comparing the DNA sequences of healthy and mutated samples, different diseases like cancers can be diagnosed.

DNA sequencing was first identified by Frederick Sanger in the 1970s. In Sanger sequencing, the target DNA is copied many times by making fragments of different lengths. At the end of the Sanger sequencing, the tube will contain different fragment lengths ending at each of the nucleotide position in the original DNA. In this technique, the florescent chain terminator nucleotides mark the ends of the fragments. They also allow the sequence to be determined. Thus, from the colours of dyes that will record one after another on the detector, the sequence of the original DNA can be built up.

For the past few years, various new DNA sequencing techniques have been evolved, such as next generation sequencing. The next generation sequencing is a large-scale approach that increases the speed of DNA sequencing. It also reduces the cost of DNA sequencing.

What are the Similarities Between DNA Profiling and DNA Sequencing?

• DNA profiling and DNA sequencing both are molecular biological techniques.
• They are both based on DNA.
• Both use PCR and gel electrophoresis in common.
• These techniques are very important to identify the genome of an individual.
• Both techniques have broad application in forensic science.
• Moreover, they can be applied in paternity testing.

What is the Difference Between DNA Profiling and DNA Sequencing?

DNA profiling is a method used to identify an individual from a sample by looking at the unique patterns in the DNA. On the other hand, DNA sequencing is a method used to determine the sequence of nucleotides in a piece of DNA of an individual. So, this is the key difference between DNA profiling and DNA sequencing. Furthermore, the objective of DNA profiling is to detect variation in human DNA in the form of minisatellites. In contrast, the objective of DNA sequencing is to determine the sequence of nucleotides that make up the DNA molecule.

The following infographic presents the differences between DNA profiling and DNA sequencing in tabular form.

Summary – DNA Profiling vs DNA Sequencing

DNA profiling and DNA sequencing are two main molecular biological techniques. They have vast applications in forensic science, medical diagnosis, biotechnology, virology, and biosystematics. DNA profiling is used to identify an individual from a sample by looking at the unique patterns in the DNA while DNA sequencing is used to determine the sequence of nucleotides in a piece of DNA of an individual. Thus, this is the summary of the difference between DNA profiling and DNA sequencing.

Reference:

1. “DNA Profiling.” Science Learning Hub.
2. “DNA Sequencing | Biotechnology.” Khan Academy.

Image Courtesy:

1. “DNA Profiling – RFLP Analysis” By Phoenix_src – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Sanger-sequencing” By Estevezj – Own work (CC BY-SA 3.0) via Commons Wikimedia