Sources of DNA Evidence

• The biological material used to determine a DNA profile include blood, semen, saliva, urine, feces, hair, teeth, bone, tissue and cells.

The process behind DNA Testing

1. Extraction is the process of releasing the DNA from the cell.
2. Quantitation is the process of determining how much DNA you have.
3. Amplification is the process of producing multiple copies of the DNA in order to characterize it.
4. Separation is the process of separating amplified DNA products to permit subsequent identification.
5. Analysis & Interpretation is the process of quantitatively and qualitatively comparing DNA evidence samples to known DNA profiles.
6. Quality Assurance is the process of reviewing analyst reports for technical accuracy

How the Results are Interpreted

• The DNA analysis process provides the analyst with a chart called an electropherogram, which displays the genetic material present 

What are nucleic acids?

• Nucleic acid is a naturally occurring chemical compound that is capable of being broken down to yield phosphoric acid, sugars, and a mixture of organic bases (purines and pyrimidines).
• Nucleic acids are the main information-carrying molecules of the cell.
• By directing the process of protein synthesis, they determine the inherited characteristics of every living thing.
• The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). 

What is DNA?

• DNA replicates and stores genetic information. It is a blueprint for all genetic information contained within an organism
• DNA consists of two strands, arranged in a double helix. These strands are made up of subunits called nucleotides. Each nucleotide contains a phosphate, a 5-carbon sugar molecule and a nitrogenous base.
• The bases in DNA are Adenine (‘A’), Thymine (‘T’), Guanine (‘G’) and Cytosine (‘C’).
• DNA is found in the nucleus, with a small amount of DNA also present in mitochondria.

Why in News:

• The Supreme Court has recently held that compelling an unwilling person to undergo a DNA test would be a violation of his/her personal liberty and right to privacy

Precedents set by court

• Judges cannot order genetic tests as a “roving enquiry” ( Bhabani Prasad Jena, 2010)
• They must balance “the interests of the parties” ( Banarsi Dass, 2005); DNA tests should also not be ordered if there was other material evidence at hand to prove the case.
• In Ashok Kumar judgment, judges, before ordering a genetic test, should examine “proportionality of the legitimate aims” being pursued.

Reference:

1. DNA Technology (Use and Application) Regulation Bill, 2019
2. https://www.thehindu.com/news/national/as-demand-grows-court-mandated-dna-tests-walk-the-fine-line-between-justice-and-privacy/article66073844.ece