EXPERIMENT REPORTISOLATION OF DNA FROM STRAWBERRY

CREATED BY:

ENIK EKAWATI K3308004DIAH MEGASARI T K3308015ANIS WIGIANI K3308026NINA ARIESTA K3308045NOVITA ROSE K3308046SUSI SUGIHARTI K3308055TANIA OKTABRI K K3308057FIAN TOTIANA K3308080

CHEMICAL EDUCATION

TEACHER TRAINING AND EDUCATION FACULTY

SEBELAS MARET UNIVERSITY

SURAKARTA

2011ISOLATION 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 ml

5 Ethanol 90% sufficient

D. PROCEDURE

Numb Step Image

1Place strawberries in a plastic

resealable bag and smunch

2

Add liquid soap for amount : 5

drops, 10 drops, 15 drops, and 20

drops.

3 Add a small amount of water (5 ml)

4 Add a pinch of salt

5 Filter the strawberry mess

6 Add 90% ethanol

7 Spool

E. OBSERVATION DATA

Numb Step Data

1Place strawberries in a plastic

resealable bag and smunch

Stroberries has broken become a little

pieces.

2

Add liquid soap for amount : 5

drops, 10 drops, 15 drops, and 20

drops.

There are a mixture between

strawberry and soap

3 Add a small amount of water (5 ml) The mixture of strawberry is red

4 Add a pinch of salt Salt has disolved

5Filter the strawberry mess Filtrate is red

The sediment has left in filter paper

6

Add 90% ethanol The mixture become two parts:

Top layer is clear solution and there

are white fiber in a mixture

Down layer is red

7 Spool

The DNA looked like white, thin

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

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