DNA Fingerprinting vs. DNA Profiling
| Component | DNA Fingerprinting | DNA Profiling |
|---|---|---|
| Basic Idea | It’s like making a visual "barcode" of a person’s DNA | It’s about analyzing specific sections of DNA for ID(identification) |
| Focus | Produces a pattern or image of DNA fragments | Focuses on unique DNA markers, like STRs |
| Technology Used | Based on RFLP (older technique) | Uses modern PCR & STR methods |
| Accuracy | Less precise, more visual | Highly accurate, widely used in forensic science |
| Use Today | Mostly outdated, rarely used | Standard method today in courts, forensics, paternity tests |
| Output | Gel image with bands (like a fingerprint) | Numeric or digital DNA profile |
- DNA – Deoxyribonucleic Acid
→ The hereditary material found in the cells of all living organisms. RFLP – Restriction Fragment Length Polymorphism
→ An older technique used in DNA fingerprinting that cuts DNA into fragments using restriction enzymes.PCR – Polymerase Chain Reaction
→ A method used to amplify (make many copies of) a small segment of DNA.STR – Short Tandem Repeat
→ Specific repeating sequences in DNA that vary among individuals; key markers used in DNA profiling.
Identical Twins and DNA:
Genetic Identity at Birth:
Identical twins (also called monozygotic twins) come from the same fertilized egg.
As a result, they share nearly 100% of their DNA sequence.
So, in standard DNA profiling, they cannot be distinguished — their DNA profiles will be identical.
However… Minor Differences Exist:
Epigenetic changes (chemical modifications to DNA that affect gene expression) and mutations that occur after the zygote splits can lead to tiny differences.
Advanced techniques like whole genome sequencing or mutation-level comparison may detect minor genetic variations between identical twins — but this is not used in routine forensic DNA tests.
So DNA Profiling cannot distinguish the identical twins