Laboratory experiment – extraction of DNA from strawberries Essay

Introduction

Deoxyribonucleic acid, short for deoxyribonucleic acid, is present in all life organisms’ cells. It contains a set of instructions that direct the activities of the organism’s development and map. ( Buddies, 2013 ) It is located within a karyon ; a membrane-bound cell organ. ( University of Queensland, 2011 ) Surrounding the karyon, there is the cell wall, chondriosomes, vacuoles, endoplasmic Reticulum, Golgi setup, lysosomes and etc. Deoxyribonucleic acid is composed of three parts: nitrogen-bearing bases ( A, T, G and C ) , sugars and phosphates which form a dual spiral with the linkage of H bonds. ( University of Queensland, 2011 )

In this lab experiment, fresh strawberries were used because strawberry cells could give more Deoxyribonucleic acid than any other fruit for the ground that they are octoploids. ( Buddies, 2013 ) This means that each strawberry cell has eight transcripts its genome ; hence they are able to supply a greater sum of extracted DNA for pupils to see. ( Buddies, 2013 ) Strawberries besides contain bantam enzymes, pectinases and cellulases, which are able to assist to interrupt down cell walls and do the DNA extraction procedure easier and more efficient. ( Sweeney, 2012 ) This activity will show how Deoxyribonucleic acid can be separated from all the other parts of the cell utilizing common family stuffs. The intent of this experiment is to larn how to pull out strawberry Deoxyribonucleic acid by merely utilizing mundane family merchandises and for pupils to see a big sample of seeable Deoxyribonucleic acid because it is predicted that strawberry DNA will be successfully extracted and will go seeable to the bare oculus.

Materials and Methods:

Three strawberries were put into the microwave and heated for approximately 12 seconds. Next, green roots were removed, and the strawberries were crushed and mashed into strawberry juice by a liquidizer alternatively of utilizing custodies for a better consequence. Then, the strawberry juice was poured into a Ziploc bag along with 2 pip-squeaks of buffer ( a mixture of Dawn dish soap, salt and tap H2O. ) Followed after, the solution was assorted within the Ziploc bag and it was poured into a clean beaker through a large ball of cheese fabrics that was folded twice for best filtration consequences. Afterwards, chilled 99 % ethyl alcohol was easy and carefully poured into the smaller beaker, non upseting the strawberry mixture ( ethanol droplets rolled down the sides of the beaker easy. ) Observations took topographic point after ethyl alcohol was poured, and the precipitate was collected with toothpicks. Consequences and observations were recorded.

Consequences:

After adding the chilled ethyl alcohol to the filtered strawberry mixture, two stages became seeable ; ethanol stage and strawberry solution stage. There was a seeable spliting line between them. Within the in-between subdivision of the two stages, precipitate formed. String sections of clear and white gooey substance quickly rose to the surface of the ethyl alcohol while the remainder of the mixture remained the same.

Discussion:

The precipitate formed in the experiment was strawberry DNA. When they were extracted from the strawberry cells, they appeared to be gluey, algae-like, clear and pinkish substances. Webs of DNA could be seen ; drifting on the surface of the ethyl alcohol, and they proved this experiment to be successful. The following are the grounds why this was a successful experiment.

First of all, strawberries were mashed and crushed in the really beginning because it will assist to physically divide the single strawberry cells. ( Buddies, 2013 ) This procedure is besides able to assist to interrupt down cell walls, cell membranes and atomic membrane ; leting the Deoxyribonucleic acid that lies in the karyon to get away into the solution. By intermixing the strawberries into bantam pieces and doing strawberry juice, cell cell organs like chondriosomes, vacuoles and lysosomes will besides be separated and mixed into the solution. ( Sweeney, 2012 ) Next, droplets of a buffer that consisted dish detergent, warm pat H2O and salt were added to the strawberry solution.

Dishwashing liquid played an of import function this lab activity because it causes strawberry cells to split unfastened, or lyse, hence doing the Deoxyribonucleic acid in the karyon to let go of into the strawberry juice. ( Sweeney, 2012 ) Just like how dish detergents could fade out fats and lipoids to clean home bases and bowls, the chemicals in the detergents besides have the ability to fade out the phospholipid subdivisions of the cell walls and proteins from atomic membranes during DNA extraction. ( Buddies, 2013 ) This procedure of cell walls interrupting apart is called cell lysis, and with the protective barriers being disrupted, DNA and other contents of the cell will be allowed to flux into the solution. ( Sweeney, 2012 ) This leads to the 3rd measure in DNA extraction.

The ground why salt, or NaCl, was necessary in this experiment is that it can make an environment where DNA strands could garner up and clop together ; which would ensue in more seeable DNA strands at the terminal. ( Wasserman, 2010 ) The salt besides causes some measures of the cellular dust from cell lysis to precipitate out of the strawberry mixture while still maintaining DNA undisturbed in the solution. ( Wasserman, 2010 ) Another ground why salt was used is that Na chloride helps to interrupt protein ironss that are bound around nucleic acids and prevents them from precipitating along with the Deoxyribonucleic acid when ethyl alcohol is added. ( Buddies, 2013 ) The last and most of import ground of all is that the phosphate compounds ( PO₄^3-) in Deoxyribonucleic acid molecules are negatively charged, and they could be neutralized by the positive NaCl ions. ( Wasserman, 2010 ) This is an highly of import function because without this neutralisation, the phosphate ions would stay negatively charged in the aqueous solution and ethyl alcohol would non be able to draw and precipitate out the Deoxyribonucleic acid bunchs. ( Buddies, 2013 )

Warm pat H2O was added to the buffer solution because the heat would rush up the chemical reaction of cell lysis and every bit good as the neutralisation of NaCl and phosphate ions. ( University of Queensland, 2011 ) Filtration took topographic point right after. This is because the salt in the buffer solution caused many cell dusts and cell organs to divide out. ( Buddies, 2013 ) When the mixture is being poured and filtered out through beds of cheese fabrics, the bigger cell residues that are non needed would be trapped and separated from the liquid solution. ( Buddies,2013 ) The Deoxyribonucleic acid, along with the strawberry mixture would go through through and flux down the little beaker.

Ethanol was the last factor that made DNA precipitate. Deoxyribonucleic acid and H2O molecules are both polar molecules and harmonizing to the regulation “like dissolves likes, ” DNA could be easy dissolved in H2O. ( Zumbo, 2012 ) However, after NaCl cations neutralized the phosphate anchors of DNA, the bond between DNA and H2O molecules had decreased by a great sum. Compared to H2O, ethyl alcohol has a lower dielectric invariable. ( University of Queensland, 2011 ) With the add-on of ethyl alcohol with a concentration more than 70 % into the filtered solution, it would increase the intermolecular forces between the Na+ and phosphate ions. ( Buddies, 2013 ) Alternatively of neutralisation, the ions would fall in together and organize a stable compound- precipitate would be formed during this procedure. In decision, the add-on of ethyl alcohol would do the DNA strands to lift up to the surface, to precipitate and to be seen with the bare oculus. ( Zumbo, 2012 )

The ground why the ethyl alcohol was chilled and iced is because this would increase the output of DNA extracted. ( University of Queensland, 2011 ) Since Deoxyribonucleic acid strands are held together by H bonds, without the protection of atomic membranes and cell membranes, they will go really delicate in warm environments. ( Zumbo, 2012 ) Cold ethyl alcohol besides helps to decelerate down the activity of DNases, or limitation enzymes that protect cells from viruses by destructing any Deoxyribonucleic acid in the cytol. ( Zumbo, 2012 ) Therefore, chilled ethyl alcohol would protect the DNA strands from damaged and later taking to a greater output of extracted strawberry DNA. ( Buddies, 2013 )

Uses for Extracted Strawberry DNA

Not merely does strawberry DNA provide pupils with acquisition and biological science cognition, it besides helps out the society in many ways. For illustration:

• Use the Deoxyribonucleic acid of a extremely disease-resistant strawberry’s cistrons for research intents ( Sweeney, 2012 )

• Surveies go arounding the evolutionary history of strawberries could take topographic point ( Sweeney, 2012 )
• Genetic research could besides take topographic point by analyzing the DNA strands of strawberries. ( Some chemicals in strawberries are known to decelerate down the growing of some tumours ) . ( Sweeney, 2012 )

Decision:

This lab activity was a success, but there are some possible stairss to take for a higher output of extracted strawberry DNA. During the filtration procedure, pupils should hold filtered out the useless strawberry cell debris more carefully. This manner, they would hold gotten a clearer DNA solution, which would so ensue in a faster and more dynamic reaction between ethyl alcohol and the filtered solution.

Merely like the anticipations in the beginning of this lab activity, the consequence was a big measure of clear, pinkish and slimed strands of Deoxyribonucleic acid that looked like spaghetti noodles. Despite of the simple process, the consequences were still highly obvious, even to the bare oculus. It was truly easy to see the white DNA strands within the reddish-pink strawberry juice solution. Overall, it was a successful and interesting experiment, and a nice sum of cognition was gained throughout the procedure.

Bibliography

Buddies. ( 2013, January 31 ) . Spongy Science: Extract Deoxyribonucleic acid from Smashed Strawberries.Scientific

American. Retrieved March 29, 2014, from hypertext transfer protocol: //www.scientificamerican.com/article/squishy-

science-extract-dna-from-smashed-strawberries/

Sweeney, D. ( 2012, October 20 ) . DNA Isolation from Strawberries.Department of Genome Sciences.

Retrieved March 30, 2014,

from hypertext transfer protocol: //www.gs.washington.edu/outreach/dhillon_dnaprocedure.pdf

University of Queensland. ( 2011 ) The University of Queensland.Strawberry DNA extraction experiment.

Retrieved March 30, 2014, from hypertext transfer protocol: //www.imb.uq.edu.au/strawberry-dna-extraction-

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Wasserman, R. ( 2010, May 11 ) . Why Is Sodium Used in DNA Extraction? .eHow. Retrieved March 30,

2014, from hypertext transfer protocol: //www.ehow.com/about_6504902_sodium-used-dna-extraction_.html

Zumbo. ( 2012 ) . Ethanol Precipitation.DEPARTMENT OF PHYSIOLOGY & A ; BIOPHYSICS. Retrieved March 30,

2014, from hypertext transfer protocol: //physiology.med.cornell.edu/faculty/mason/lab/zumbo/files/ETHANOL_PRECIP

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