DNA Identification | The Science Behind Forensic DNA Profiling and the Red Fort Blast Investigation

What Is DNA Identification and Why Was It in the News?

• DNA Identification (or DNA Profiling) was recently used to identify suspects and victims in the Red Fort blast investigation.
• It is a scientific technique that identifies individuals by analyzing unique patterns within their DNA sequences.
• Every individual, except identical twins, has a distinct DNA profile, making this method highly accurate and reliable.

What Exactly Is DNA?

• DNA (Deoxyribonucleic Acid) is the genetic material that carries hereditary information in all living organisms.
• Each person’s DNA sequence contains regions that vary greatly among individuals.
• These variable regions form the basis of DNA profiling, allowing scientists to differentiate one person’s DNA from another’s.
• DNA profiling works by comparing variable DNA regions between samples collected from crime scenes and known individuals.

What Are the Key Methods Used in DNA Identification?

1. Short Tandem Repeat (STR) Analysis
2. STR Analysis examines short, repeating DNA sequences found in the nucleus of cells.
3. The number of repeats in these sequences varies among individuals, creating a unique genetic signature.
4. STR analysis is the most widely used method in forensic investigations.
5. It is valued for its high accuracy, sensitivity, and ability to work with minimal DNA samples.
6. Mitochondrial DNA (mtDNA) Analysis
7. When nuclear DNA is damaged or degraded, scientists analyze mitochondrial DNA (mtDNA) instead.
8. mtDNA is found in the mitochondria, which are energy-producing organelles inside cells.
9. It is maternally inherited, meaning it is passed only from mother to child without recombination.
10. Because of this, mtDNA can be matched with maternal relatives to help identify victims or missing persons.
11. It is especially useful for old, burned, or decomposed samples where nuclear DNA cannot be retrieved.
12. Y Chromosome Analysis
13. This method examines Short Tandem Repeats (STRs) present on the Y chromosome.
14. The Y chromosome is passed from father to son, forming a continuous male lineage.
15. This technique helps identify male victims or establish paternal relationships among individuals.
16. It is particularly useful in cases involving male suspects or familial lineage tracing.

• Single Nucleotide Polymorphism (SNP) Analysis
• SNPs (Single Nucleotide Polymorphisms) are single-base variations at specific positions in the DNA sequence.
• Each person has a unique SNP pattern, serving as a precise genetic identifier.
• SNP analysis is especially valuable when working with highly degraded DNA samples.
• It can confirm identity using DNA from personal items like toothbrushes, hair combs, or razors.

What Is the Significance of DNA Identification?

• DNA profiling provides scientific and legally admissible evidence that can link suspects to crime scenes with high certainty.
• It plays a critical role in disaster victim identification (DVI) and missing person investigations.
• The technique is non-invasive, highly reliable, and can analyze trace or damaged biological materials.
• In the Red Fort blast case, DNA profiling helped identify human remains and contributed to the forensic reconstruction of events.

Why Is DNA Profiling Important for Governance and Law?

• DNA technology enhances criminal justice, ensuring accurate identification and preventing wrongful convictions.
• It is used under legal frameworks such as the DNA Technology (Use and Application) Regulation Bill to govern collection and use.
• The technique is vital for national security, terror investigations, and humanitarian identification efforts.

DNA identification represents a cornerstone of modern forensic science — combining genetics, technology, and law enforcement. With advanced methods like STR, mtDNA, Y-chromosome, and SNP analysis, it ensures precision even in degraded or complex samples.

As India strengthens its forensic and counterterrorism capabilities, DNA profiling remains a powerful tool in delivering justice and ensuring accountability.