HOME DETERGENTS AND DNA
EXTRACTION FROM FRUIT
Dana Hogan
Problem
• Testing which home detergent- shampoo, laundry
detergent, or dishwashing detergent- most effectively
extracts DNA from kiwi
Research
• DNA, or deoxyribonucleic acid, is the genetic material for all
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living things that can be found in the cell nucleus.
DNA extraction is the removal of deoxyribonucleic acid from the
cells or viruses in which it can normally be found.
In a basic DNA extraction, the steps included: lyses of tissue
and/or cells, precipitating the DNA, the application of a
detergent, and heat denaturation.
The kiwifruit, or Actinidia deliciosa, is made-up mainly of sugar
and ascorbic acid.
A surfactant, a main component of cleaning detergents, is a
substance that has the ability to remove dirt, grease, or oil from
other surfaces when it is added to water.
Previous student studies on the subject of the effectiveness of
home detergents and DNA extraction from fruit found that
laundry detergent proved the most effective.
Hypothesis
• If the effectiveness of shampoo, laundry detergent, and
dishwashing detergent in DNA extraction from fruit were
tested, then dishwashing detergent would prove the most
effective.
Materials
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pH paper
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200mL cold ethanol
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Volumetric flask
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Freezer
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Balance weighing to
.01g
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Balance weighing to
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.001g
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Small blender
Fork and knife
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480g mashed kiwi
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20mL Suave® shampoo •
20mL all® laundry
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detergent
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20mL Seventh
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Generation™
dishwashing detergent •
360mL distilled water
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8g salt
500mL beaker
100mL graduated
cylinder
6 200mL beakers
Hot water bath
Thermometer
2 large Tupperware
containers
Ice
Cheesecloth
Coffee filters
6 1000mL beakers
Filter
Strainer
10mL graduated
cylinder
20 test tubes
• Glass stirring rod
• Small metal hook
• Weighing paper
Procedure
• PH balance of detergents was tested.
• A salt-water solution of 180mL of water and 4g of salt was prepared.
• 60g mashed kiwi were poured into a 200mL beaker and researcher 10mL
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detergent and 30g salt-water solution were added.
Mixture heated in hot water bath at 50ºC for 10 minutes, stirring occasionally.
Mixture transferred to ice bath for 5 minutes.
Cooled mixture was filtered into 1000ml beaker. (In first set of trials, cheesecloth
was used for filtration, whereas in the second set of trials, coffee filters were used
for filtration.)
Once 15mL of filtrated were gathered, 3 test tubes with 5mL of filtrate each were
filled.
10mL of cold ethanol were carefully poured into each test tube.
Test tubes placed in ice bath for 5 minutes.
Spooling of visible DNA was attempted.
Spooled DNA was spread onto pre-weighed weighing paper and let dry for 2
days.
Mass of DNA extracted was calculated.
This procedure was repeated twice for shampoo and dishwashing detergent
samples. In the first set of trials, 1 control sample was tested, but in the second
set of trials, 3 control samples were tested. In first set of trials, 3 samples of
laundry detergent were tested, but in the second set, 1 sample was tested.
Variables
• Independent variable- type of detergent added
• Dependent variable- amount of DNA extracted
• Control- samples without detergent
• Constants- amount of salt-water, kiwi, and detergent
added, temperature during incubation, length of time
allotted for incubation and cooling, amount of filtrate used,
amount of ethanol added to filtrate
Data
DNA Extracted from Each Sample (g)
Control
Shampoo
Laundry
Dish (1)
Dish (2)
Trail 1
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0.01
0.124
Trial 2
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0.02
0.099
Trial 3
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0.095
Average
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0.01
0.106
Data
Average of DNA Extracted (g)
Average DNA Collected (g)
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
Control
Shampoo
Laundry
Detergent
Dish (1)
Dish (2)
Photos
Conclusion
• The purpose of this experiment was to see which home
detergent- shampoo, laundry detergent, or dishwashing
detergent- would most effectively extract DNA from fruit.
• The hypothesis that if the effectiveness of shampoo,
laundry detergent, and dishwashing detergent in DNA
extraction from fruit were tested, then dishwashing
detergent would prove the most effective was supported.
• Knowledge gained through this experiment can help find
more cost effective methods of DNA extraction for various
purposes, whether it is in schools or advanced
laboratories.
Discussion
• Possible errors that occurred during experimentation
include different filtration methods, varying methods for
mashing the kiwi, and the temperature of the ethanol.
• If repeated, more samples would be tested, coffee filters
would consistently be used as the method of filtration, a
balance measuring to .001 would be consistently used,
and the ethanol would remain in the freezer up until it was
needed.
• Further experimentation could include testing different
types of fruits and organic vs. nonorganic detergents.
References
• Bachor, K. (n.d.). The best detergent for plentiful DNA extraction. Retrieved from
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http://www.odec.ca/projects/2006/bach6k2/index.htm
Berlow, L. H. (2011). Laundry detergent. Retrieved from eNotes.com, Inc. website:
http://www.enotes.com/how-products-encyclopedia/laundry-detergent
Morton, J. F. (1987). Fruits of warm climates (pp. 293-300). Retrieved from
http://www.hort.purdue.edu/newcrop/morton/kiwifruit_ars.html
Ombrello, T. (n.d.). The Pineapple. Retrieved from http://faculty.ucc.edu/biologyombrello/pow/pineapple.htm
Rice, G. (2010, October 28). DNA extraction. Retrieved from
http://serc.carleton.edu/microbelife/research_methods/genomics/dnaext.html
Strawberry. (2011). In Britannica. Retrieved from
http://www.britannica.com/EBchecked/topic/568585/strawberry
Surfactants. (2005). Retrieved from Procter&Gamble website:
http://www.scienceinthebox.com/en_UK/glossary/surfactants_en.html
Understanding automatic dishwashing. (2010). Retrieved from American Cleaning Institute
website:
http://www.cleaninginstitute.org/clean_living/understanding_automatic_dishwashing.aspx#De
tergent
What is DNA? (2011, October 4). Retrieved from US National Library of Medicine website:
http://ghr.nlm.nih.gov/handbook/basics/dna
What is hair shampoo? (2011). Retrieved from Herbal Luxuries Natural Skin Care & Acne
Products website: http://www.herballuxuries.com/what-is-hair-shampoo.html
World of Forensic Science. (2005). DNA isolation methods. Retrieved from
Encylcopedia.com website: http://www.encyclopedia.com/topic/DNA_Isolation_Methods.aspx