Name: Nadia Jacobs
Instructor: Professor Garrick
Date: 11/22/2024
Title: Isolation of DNA from Onion cells
Objective(s)/Aim(s): The aim of this experiment is to isolate DNA from onion cells, separate it
from other cellular components using a precipitation technique, and observe the unique
viscosity of the long DNA molecules that allows them to be spooled. This activity provides a
hands-on understanding of DNA’s structure, properties, and the molecular biology techniques
used to extract and study it, reinforcing theoretical concepts with practical application.
Introduction: DNA, or deoxyribonucleic acid, is the molecule that carries genetic information
essential for life. Despite its critical role, it often remains an abstract concept for students. This
experiment focuses on isolating DNA from onion cells, providing a hands-on approach to
observe and understand its structure and properties. Using a simple and cost-effective protocol,
the process involves breaking down cell walls and membranes with a homogenizing solution
and precipitating DNA using cold ethanol. This “low-tech” method offers a practical and reliable
way to isolate and visualize DNA, allowing students to connect theoretical knowledge with
tangible results while gaining insights into molecular biology techniques.
Materials and Methods:The materials used in this experiment include onions, a homogenizing
solution (containing NaCl, EDTA, and SDS), ice-cold 95% ethanol, and basic laboratory
equipment such as a blender, beakers, conical centrifuge tubes, cheesecloth, and Pasteur pipet
hooks. The method begins with dicing the onion, mixing it with the homogenizing solution, and
incubating it at 60°C to break down cell walls and denature proteins. The mixture is then
blended to release cellular components, cooled in an ice bath, and filtered through cheesecloth
to remove debris. The filtrate is transferred to a centrifuge tube, where ice-cold ethanol is
layered to precipitate the DNA. Finally, the DNA is spooled using a Pasteur pipet hook and
stored in ethanol for further observation. This straightforward procedure allows for effective
isolation and visualization of DNA.
Results:
Instructor: Professor Garrick
Date: 11/22/2024
Title: Isolation of DNA from Onion cells
Objective(s)/Aim(s): The aim of this experiment is to isolate DNA from onion cells, separate it
from other cellular components using a precipitation technique, and observe the unique
viscosity of the long DNA molecules that allows them to be spooled. This activity provides a
hands-on understanding of DNA’s structure, properties, and the molecular biology techniques
used to extract and study it, reinforcing theoretical concepts with practical application.
Introduction: DNA, or deoxyribonucleic acid, is the molecule that carries genetic information
essential for life. Despite its critical role, it often remains an abstract concept for students. This
experiment focuses on isolating DNA from onion cells, providing a hands-on approach to
observe and understand its structure and properties. Using a simple and cost-effective protocol,
the process involves breaking down cell walls and membranes with a homogenizing solution
and precipitating DNA using cold ethanol. This “low-tech” method offers a practical and reliable
way to isolate and visualize DNA, allowing students to connect theoretical knowledge with
tangible results while gaining insights into molecular biology techniques.
Materials and Methods:The materials used in this experiment include onions, a homogenizing
solution (containing NaCl, EDTA, and SDS), ice-cold 95% ethanol, and basic laboratory
equipment such as a blender, beakers, conical centrifuge tubes, cheesecloth, and Pasteur pipet
hooks. The method begins with dicing the onion, mixing it with the homogenizing solution, and
incubating it at 60°C to break down cell walls and denature proteins. The mixture is then
blended to release cellular components, cooled in an ice bath, and filtered through cheesecloth
to remove debris. The filtrate is transferred to a centrifuge tube, where ice-cold ethanol is
layered to precipitate the DNA. Finally, the DNA is spooled using a Pasteur pipet hook and
stored in ethanol for further observation. This straightforward procedure allows for effective
isolation and visualization of DNA.
Results:
