DNA Test (for example, used in human identity testing, pathogen detection, or inherited disorder screening)

 


🧬 1. Objective

The objective of this test was to extract and analyze DNA from a biological sample (such as blood, saliva, buccal swab, or stool) in order to determine genetic identity, detect the presence of specific DNA sequences, or evaluate genetic mutations.

🧬 2. Principle

The DNA test was based on isolating DNA from cells, amplifying target DNA segments using polymerase chain reaction (PCR), and then detecting or comparing these sequences via gel electrophoresis, real-time PCR, or sequencing. DNA testing could detect unique genetic patterns or mutations specific to individuals or organisms.

🧬 3. Materials

  • Sample: blood, buccal swab, or stool

  • DNA extraction kit or reagents

  • Microcentrifuge tubes

  • PCR reagents (primers, Taq polymerase, dNTPs, buffer)

  • Thermal cycler (PCR machine)

  • Agarose gel and electrophoresis chamber

  • UV transilluminator or real-time PCR detector

  • Gloves and sterile pipette tips

🧬 4. Procedure

  1. DNA was extracted from the biological sample using a spin-column or magnetic bead method.

  2. The concentration and purity of extracted DNA were measured using a spectrophotometer (A260/A280).

  3. Specific gene regions were amplified using PCR with target-specific primers.

  4. Amplified products were visualized using gel electrophoresis or detected via real-time PCR fluorescence curves.

  5. Optional: DNA was sequenced for detailed analysis (e.g., Sanger sequencing).

🧬 5. Result (Example)

Test TypeResult
PCR for target genePositive (band observed at 300 bp)
DNA Match (identity)99.99% match with reference DNA
Mutation ScreeningNo mutation detected in exon 7

Example: A DNA band was observed at the expected 300 bp position, indicating a positive result for the target gene.


🧬 6. Uses

  • Human identity or paternity testing

  • Detection of genetic mutations (e.g., BRCA1/2, CFTR)

  • Pathogen detection (e.g., tuberculosis, H. pylori DNA)

  • Prenatal or carrier screening

  • Forensic analysis and crime investigation

  • Ancestry and heritage analysis

🧬 7. Conclusion

The DNA test was a highly sensitive and specific molecular technique used for genetic analysis. It played a critical role in diagnostics, research, and forensic science by allowing accurate identification of genes, organisms, or individuals.

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