Biotechnology: Principles and Processes — BIOLOGY STD 12 Science — Question

• RNA is removed by treatment with ribonuclease and proteins are removed by treatment with protease.
• After several treatments, the purified DNA is precipitated by adding chilled ethanol.
• The bacterial/ plant/ animal cell is broken down by enzymes to release DNA, along with RNA, proteins, polysaccharides and lipids.
• Bacterial cell is treated with enzyme lysozyme.
• Plant cell is treated with enzyme cellulase.
• Fungal cell is treated with chitinase.

Cutting of DNA at specific locations:

• The DNA is cut using restriction enzymes.
• The purified DNA is incubated, with the specific restriction enzyme at conditions optimum for the enzyme to act. Isolation of desired DNA fragment
• Using agarose gel electrophoresis, the activity of the restriction enzymes can be checked.
• Since the DNA is negatively charged, it moves towards the positive electrode or anode and in the process, DNA fragments separate out based on their sizes.
• The desired DNA fragment is eluted out.

Amplification of gene of interest using PCR:

• The Polymerase Chain Reaction (PCR) is a reaction in which amplification of specific DNA sequences is carried out in vitro.