Class XII Practical: Biochemical & Physiological Experiments - DNA Isolation from Plant Material

Objective

To extract and observe DNA from common plant materials like banana, spinach, pea, or papaya.

Material Preparation: Take a small amount of fresh plant material (e.g., banana pulp, spinach leaves).
Homogenization: Mash or blend the plant material thoroughly to break open cells.
Lysis Buffer Preparation: Prepare a lysis buffer containing detergent (e.g., dish soap) to break down cell membranes, salt (e.g., NaCl) to neutralize DNA charge, and water.
Incubation: Mix the homogenized plant material with the lysis buffer and incubate at a warm temperature (e.g., 50-60°C) for a short period to aid cell lysis.
Filtration: Filter the mixture through a cheesecloth or sieve to remove large debris.
Enzyme Treatment (Optional): Add a protease (e.g., meat tenderizer) to digest proteins.
DNA Precipitation: Carefully add chilled ethanol or isopropanol to the filtrate. DNA will precipitate out as white, stringy strands at the interface of the two layers.
Observation: Spool the precipitated DNA onto a glass rod or observe it floating in the alcohol layer.

Visible strands of DNA extracted from plant cells, demonstrating the presence of genetic material.

To extract and observe DNA from common plant materials like banana, spinach, pea, or papaya.

Material Preparation: Take a small amount of fresh plant material (e.g., banana pulp, spinach leaves).
Homogenization: Mash or blend the plant material thoroughly to break open cells.
Lysis Buffer Preparation: Prepare a lysis buffer containing detergent (e.g., dish soap) to break down cell membranes, salt (e.g., NaCl) to neutralize DNA charge, and water.
Incubation: Mix the homogenized plant material with the lysis buffer and incubate at a warm temperature (e.g., 50-60°C) for a short period to aid cell lysis.
Filtration: Filter the mixture through a cheesecloth or sieve to remove large debris.
Enzyme Treatment (Optional): Add a protease (e.g., meat tenderizer) to digest proteins.
DNA Precipitation: Carefully add chilled ethanol or isopropanol to the filtrate. DNA will precipitate out as white, stringy strands at the interface of the two layers.
Observation: Spool the precipitated DNA onto a glass rod or observe it floating in the alcohol layer.

Visible strands of DNA extracted from plant cells, demonstrating the presence of genetic material.