EXPERIMENT REPORT
ISOLATION OF DNA FROM STRAWBERRY
CREATED BY:
ENIK EKAWATI
K3308004
DIAH MEGASARI T
K3308015
ANIS WIGIANI
K3308026
NINA ARIESTA
K3308045
NOVITA ROSE
K3308046
SUSI SUGIHARTI
K3308055
TANIA OKTABRI K
K3308057
FIAN TOTIANA
K3308080
CHEMICAL EDUCATION
TEACHER TRAINING AND EDUCATION FACULTY
SEBELAS MARET UNIVERSITY
SURAKARTA
2011
ISOLATION OF DNA FROM STRAWBERRIES
A. OBJECTIVES

Students knowing how to extract DNA

Student can see the precipitation process of DNA

Student can isolate DNA from strawberries
B. BASIC THEORY
Since DNA is the blueprint for life, everything living contains DNA. DNA
isolation is one of the most basic and essential techniques in the study of DNA. The
extraction of DNA from cells and its purification are of primary importance to the
field of biotechnology and forensics. Extraction and purification of DNA are the first
steps in the analysis and manipulation of DNA that allow scientists to detect genetic
disorders, produce DNA fingerprints of individuals, and even create genetically
engineered organisms that can produce beneficial products such as insulin, antibiotics,
and hormones.
DNA can be extracted from many types of cells. The first step is to lyse or
break open the cell. This can be done by grinding a piece of tissue in a blender. After
the cells have broken open, a salt solution such as NaCl and a detergent solution
containing the compound SDS (sodiumdodecyl sulfate) is added. These solutions
break down and emulsify the fat & proteins that make up a cell membrane. Finally,
ethanol is added because DNA is soluble in water. The alcohol causes DNA to
precipitate, or settle out of the solution, leaving behind all the cellular components that
aren't soluble in alcohol. The DNA can be spooled (wound) on a stirring rod and
pulled from the solution at this point.
Strawberries, bacteria, humans—all living things have genes, and all of these
genes are made of DNA. That's why scientists can take a gene from one living thing
and put it into another. For example, they can put human genes into bacteria to make
new medicines.
The wild strawberry is a "diploid" - it has two sets of chromosomes, as in
humans. The most commonly cultivated strawberry, Fragaria ananassa, is an
octoploid with eight sets. This makes it a good candidate for demonstrating DNA
extraction - with eight copies of each gene in the strawberry genome, strawberries are
packed full of it. The strawberry, it turns out, has a long and complicated family
history. The cultivated strawberry is interesting from a genomic perspective, because
it's a polyploid hybrid species. Unlike peas, for example, or humans, for that matter,
which are diploids (with two sets of chromosomes), a strawberry is an octoploid (with
eight sets of chromosomes). How some strawberries evolved from diploids to
octoploids is part of the story that people are trying to unravel.
Many people are surprised to find out that strawberry growers plant bare-root
plants rather than seeds. The reason is every strawberry seed contains different genetic
material, the product of a myriad of potential gene combinations. Because the genetics
of strawberries are so diverse (humans are diploid, strawberries are octoploid).
For
strawberries, the mother plant puts out runners (called daughter plants) that were
essentially identical to her, which in turn also put out runners.
One of the reasons strawberries work so well is that they are soft and easy to
pulverize. Also, ripe strawberries produce enzymes (pectinases and cellulases) which
aid in breaking down the cell walls. Most interestingly, strawberries have enormous
genomes.
They are octoploid, which means they have eight of each type of
chromosome (which equals abundant DNA).
C. TOOL AND MATERIAL
1. Tools
Numb
Name of Tool
Image
Amount
1
Releable bag
1
2
Test tube
4
3
Beaker glass
1
4
Meassuring glass
1
5
Test tube rack
1
6
Pipette
4
7
Glass funnel
2
8
Filter paper
4
9
Stirer
2
2. Materials
Numb
Name of Material
Amount
1
Strawberries
1
2
Liquid soap
50 drops
3
Salt
Sufficient
4
Water
5
Ethanol 90%
5 ml
sufficient
D. PROCEDURE
Numb
1
Step
Place strawberries in a plastic
resealable bag and smunch
Add liquid soap for amount : 5
2
drops, 10 drops, 15 drops, and 20
drops.
3
Add a small amount of water (5 ml)
Image
4
Add a pinch of salt
5
Filter the strawberry mess
6
Add 90% ethanol
7
Spool
E. OBSERVATION DATA
Numb
1
2
Step
Data
Place strawberries in a plastic
Stroberries has broken become a little
resealable bag and smunch
pieces.
Add liquid soap for amount : 5
There are a mixture between
drops, 10 drops, 15 drops, and 20
strawberry and soap
drops.
3
Add a small amount of water (5 ml)
The mixture of strawberry is red
4
Add a pinch of salt
Salt has disolved
Filter the strawberry mess
Filtrate is red
5
The sediment has left in filter paper
Add 90% ethanol
The mixture become two parts:
Top layer is clear solution and there
6
are white fiber in a mixture
Down layer is red
The DNA looked like white, thin
7
Spool
fibers wadded up together forming a
clump.
F. DISCUSSION
This experiment has purposes to know how to extract DNA, to see the
precipitation process of DNA, and the main purpose is isolated DNA from strawberry.
This is a simple, effective protocol for spooling DNA. Ripe strawberries are an
excellent source for extracting DNA because they are easy to pulverize and contain
enzymes called pectinases and cellulases that help to break down cell walls. And most
important, strawberries have eight copies of each chromosome (they are octoploid), so
there is a lot of DNA to isolate.
The first step in this procedure is placed strawberries in a plastic and smunch.
This step has done to break the strawberry. It will destroy the cell wall and cell
membrane, which is used here is water and wrung. We recall the principles of cell
biology, namely diffusion-osmosis, where much less pressure coming in higher cells,
the cell will be damaged. In this step, supernatant / fluid contains organelles within the
cell and of course there is also DNA. But here the DNA was still inside the nucleus.
Then the second step is adding liquid soap for amount : 5 drops, 10 drops, 15
drops, and 20 drops. We know that DNA is still in the nucleus. Well, to destroy and
remove the nucleus of our DNA with the provision of soap treatment. This is because
most of the nuclear membrane is fat, to eliminate the fat we need soap. The soap helps
to dissolve the phospholipid bilayers of the cell membrane and organelles.
The next steps is adding a small amount of water and then add a pinch of salt.
The salt helps keep the proteins in the extract layer so they aren’t precipitated with the
DNA.
Then filter the strawberry mess. In this step we get the red filtrate while the
sediment or dregs left in the filter paper. After that add the 90% ethanol to the filtrate.
This addition resulted in the formation of two layers where the bottom layer is red
while the upper layer of clear liquid and there are white clumps of thread. Alcohol is
less dense than water, so it floats on top forming two separate layers. All of the grease
and the protein that we broke up in the first two steps move to the bottom, watery
layer. DNA will rise into the alcohol layer from the pea layer. DNA is not soluble in
ethanol. When molecules are soluble, they are dispersed in the solution and are
therefore not visible. When molecules are insoluble, they clump together and become
visible. The colder the ethanol, the less soluble the DNA will be in it yielding more
visible “clumping.” This is why it is important for the ethanol to be kept in a freezer
or ice bath.
The last step in this experiment is spooling. This step has purpose to collect the
DNA that has been isolated by all the procedure.
Single molecules of DNA are long and stringy. Each cell of the body contains
six feet of DNA, but it's only one-millionth of an inch wide. To fit all of this DNA into
the cells, it needs to be packed efficiently. To solve this problem, DNA twists tightly
and clumps together inside cells. Even when DNA extracted from cells, it still clumps
together, though not as much as it would inside the cell.
The DNA that occur is white, stringy stuff actually a mix of DNA and RNA.
That because of the procedure for DNA extraction is really a procedure for nucleic
acid extraction. However, much of the RNA is cut by ribonucleases (enzymes that cut
RNA) that are released when the cells are broken open.
G. ANSWER OF QUESTION
1. Place 1 strawberry in a plastic, resealable bag and smunch to break the strawberry
in order to destroy the cell wall and cell membrane.
2. Adding liquid soap has purpose to destroy and remove the nucleus of DNA with
the provision of soap treatment. The soap helps to dissolve the phospholipid
bilayers of the cell membrane and organelles.
3. Adding a small amount of water to help destroying the cell wall and cell
membrane of strawberry.
4. Adding a pinch of salt has to remove proteins that are bound to the DNA. It also
helps to keep the proteins dissolved in the aqueous layer so they don’t precipitate
in the alcohol along with the DNA.
5. Filtering strawberry mess is to remove the larger particles from the solution, such
as seeds, pith, etc., allowing only the smaller cell components such as the DNA,
proteins, etc. to filter through.
6. Adding 90% alcohol causes the DNA to precipitate.
7. Spooling has done to take the DNA of strawberry that has been obtained.
H. CONCLUSION
1. DNA is is a nucleic acid that contains the genetic instructions used in the
development and functioning of all known living organisms. DNA is a large
polymer with unique physical characteristics of property.
2. Isolation of DNA can be done by simple method by using water, soap, salt, and
alcohol.
3. The function of adding some materials:

Soap, dissolve the phospholipid bilayers of the cell membrane and organelles

Water, help destroying the cell wall and cell membrane of strawberry

Salt (Sodium Chloride), remove proteins that are bound to the DNA

90% ethanol, causes the DNA to precipitate
4. In this experiment we get the DNA looked like white, thin fibers wadded up
together forming a clump.
I. BIBLIOGRAPHY
Aldina Wildan.2011. Lab report the basics of biotechnology. Semarang State
University
2010. DNA Isolation from Strawberry. http://www.science-projects.com/index.html
2011. DNA. http://en.wikipedia.org/wiki/DNA
Surakarta, December 15th 2011
Practicants