Context: In the tragic railway accident that took place in Balasore in Odisha, the administration is facing a challenge of identifying people. In order to identify people, A DNA testing centre has been created at AIIMS to identify people and give the bodies to respective family members.
What is DNA Sampling?
DNA sampling refers to the collection and analysis of DNA (deoxyribonucleic acid) samples from individuals. DNA is the genetic material that carries the instructions for the development and functioning of living organisms.
What are the ways to collect DNA Sample?

Following are the ways to collect DNA sample:
- By collecting cheek swab
- By drawing blood
- By taking saliva sample
- In new born, through heel prick
- Amniocentesis for pregnant women
- Chorionic villus sampling for 10-13 week old featus
- Fine needle aspiration
For forensic studies, DNA is collected from following sources:

DNA sampling is used in various contexts, including forensic investigations, paternity testing, and medical research. Here’s how it is commonly used to identify people:
- Forensic DNA Sampling: In criminal investigations, DNA sampling plays a crucial role in identifying suspects and linking them to crime scenes. Investigators collect DNA samples from various sources such as blood, saliva, hair, or skin cells left at the scene. These samples are then sent to a laboratory for analysis.
- DNA Profiling: The collected DNA samples are subjected to a process called DNA profiling or DNA fingerprinting. This process involves analyzing specific regions of the DNA sequence that exhibit variations between individuals, known as polymorphic regions or genetic markers.
- Polymerase Chain Reaction (PCR): PCR is a technique used to amplify specific DNA regions in the collected samples. This amplification process generates sufficient DNA material for further analysis.
- Short Tandem Repeat (STR) Analysis: STR analysis is commonly used in forensic DNA profiling. It involves identifying and comparing the lengths of short repeated sequences of DNA at specific loci. These repetitive sequences vary among individuals, making them useful for distinguishing between people.
- DNA Database Comparison: Once the DNA profile is obtained, it can be compared to profiles stored in DNA databases. These databases contain DNA profiles from known individuals, such as convicted criminals or missing persons. If a match is found, it can provide important investigative leads or help confirm a person’s identity.
- Paternity Testing: DNA sampling is also used in paternity testing to determine biological relationships between individuals. The DNA profiles of the child and potential parents are compared, and the likelihood of paternity is assessed based on the degree of similarity.
It’s important to note that DNA sampling and analysis require careful handling and adherence to strict protocols to ensure accuracy and avoid contamination. The results obtained from DNA testing can provide strong evidence in various legal, medical, and identity-related situations.