Dna Extraction Lab Report 2v412j

Dorothy Kam Y10J Effect of different ratio of the salt mixture to the width of the strawberry’s DNA Research: Extracting DNA is important to scientists, because this greatly aids scientists in finding cure to genetic disorders, new cures to these illnesses in recent years are largely thanks to DNA extraction, cures such as bone marrow transplant for sickle cell disease. Extracting DNA is important to forensic scientists, this greatly aids the investigation to quickly and accurately judge and identify suspects, sometimes this may prove to be challenging as in some cases the DNA collected of the suspect might have been mixed with other DNA or have been contaminated. The dish washing detergent is needed to break the cell membrane and the nuclear membrane, this helps the frees the DNA from the membrane protection and it also is to dissolve the proteins and lipids from the DNA, the salt helps remove fat an protein from the DNA strand as well as making the binding of DNA strands easier. The alcohol forces the DNA to bind together and become visible. Hypothesis: I think that because the salt play key parts to make the DNA visible, I think that the more salt in the mixture, the more visible and larger the DNA strands will be. Variables: independent variable variable

measurement

Explanation

salt (grams)

0g 2g 4g 6g

As salt play a big part in making the DNA strand more visible I think that adding more or less of the mixture may affect the final product.

Dependant variable variable

measurement

Explanation

DNA

visibility

This will be the final item that our group will be observing to find out the visibility of the DNA

variable

measurement

Explanation

Water bath (degrees celsius)

60°C

As the water bath temperature is not going to be changed they are the controlled variables, each assessment of the final product will have the same process and the same amount of the control variables.

Strawberries (grams)

30g

The amount of strawberries are not going to be changed, they are the controlled variables, they will be measured to 30g each time we perform the experiment each assessment of the final product will have the same process and the same amount of the control variables.

iced ethanol (millilitre)

20 ml

The amount of iced ethanol are not going to be changed they are the controlled variables, we will measure the ethanol each time with a dropper before we add it to the strawberry. The assessment of the final product will have the same process and the same amount of the control variables.

Controlled Variable

variable

measurement

Explanation

Water (milliliter)

90 ml

This is the water mixed into the strawberry solution, it is not the same as the water bath as these measurement of water are not going to be changed they are the controlled variables, the water is to change the consistency of the mashed strawberry so that there will be more juice to use when assessing the DNA, each assessment of the final product will have the same process and the same amount of the control variables.

detergent (millilitre)

10ml

As both detergent and salt play a big part in making the DNA strand more visible I think that adding more or less of the mixture may affect the final product. But as we want to focus on the breaking down the fats and protein of the DNA strands and we will try to see the direct affect of not removing the fat and protein the amount of detergent will not be different.

Strawberry mixture

1/4 of the test tube

This is to ensure a fair assessment in the amount of DNA.

Equipment: 1x 100 ml beaker 2x 150 ml beaker 1x test tube rack 1x plastic bag 1x cheese cloth 1x funnel 1x glass rod 5x test tube 1x dropper Risk Assessment:

• Glass breaking when in the experimental process • When in this situation I should tell the teacher immediately or the lab technician • Human error may have affected our results as when we poured the strawberry mixture it may not

•

•

• •

•

be the exact amount in each test-tube • To lessen the human error that is being done we have attempted to use a marker and a ruler to measure how much food we put into each test tube. the amount of DNA may be different in each part of the strawberry • Instead of measuring how big or small the strawberry is our group has mixed all the strawberries together in the process of mashing up the strawberries in the bag. The equipment may fall onto the floor for example: the glass rod may break when dropped • In cases of any glass equipment breaking or any equipment is damaged we will find either a technician or teacher to help us in resolving these difficulties. Lab coat and googles must be worn • To prevent dangerous substances to stain cloths and get into eyes. Handle flammable materials such as Ethanol with care • Ethanol is flammable ( no ignition sources nearby) • Do not drink ethanol, if drunk seek a teacher or lab technician’s help Handle dish soap with care • Do not drink dish soap, it is a poisonous substance, seek teacher and lab technician’s help is consumed.

Method: Step

Description

Reason

1

Add 10 mL of dish soap into the beaker

This step is a controlled variable, it is used to break down the membranes of the cell which holds the DNA.

2

Add 2 g of salt into the mixture This step is the independent variable, it helps break down the proteins and fats that hold onto the DNA.

3

Put two strawberry is in a bag and crush them up, measure 30g of strawberries for each experiment.

This step is the controlled variable, this is to help crush the strawberries to ensure a fair measurement to each of the experiments.

4

Add the dish soap and salt mixture into the strawberry

This step is the controlled variable, as dish soap and salt mixture help breaks down membrane of the cell, fats and protein, to ensure fair a fair experiment measure 10ml to use each time.

5

Place 30 mL of water into the strawberry and soap mixture

This step is the controlled variable, this helps make the mixture more in quantity so we can easily repeat the experiment.

6

Place 30g strawberries mixture This step is to help make the into the 60°C water bath for 10 breaking down of fats, cell minutes membrane and protein quicken. It is a controlled variable.

7

Strain the strawberry mixture

This is a mandatory step, this is to help the extraction of the DNA to be clearer as it has no pulp.

Step

Results: Trial 1:

Trial 2:

Description

Reason

8

Add the strawberry mixture into test tubes, about to the quarter line of the test tube

This is a controlled variable, to make sure it is a fair experiment we need to make sure the amount of DNA in each is fair.

9

Add 5 mL of iced ethanol into the test tube

This is a controlled variable, to make sure it is a fair experiment we need to make sure the amount of ethanol used is the same, this is measured with a dropper.

10

Wait for DNA to separate from mixture

Trial 3:

Trial 4:

Trial 5:

Results Table: Salt added in ml:

Trial1 Width in (cm)

Trial 2 Width in (cm)

Trial 3 Width in (cm)

Trial 4 Width in (cm)

Trial 5 Width in (cm)

Average

0

0.3

0.4

0.4

0.4

0.7

0.44

2

0.2

0.5

0.4

0.7

1.2

0.6

4

0.5

2.2

0.4

1.1

0.5

0.94

6

2.6

0.9

0.35

1

1.1

1.19

Graph:

Conclusion: In conclusion, the amount of salt added to the mixture slightly affects the width of the DNA. This shows that the amount of salt added into the mixture directly affects the visibility of the DNA when doing this experiment(extracting fruit DNA). This is because they salt plays a very important role in breaking down protein and fats in the cell. My hypothesis (I think that because the salt play key parts to make the DNA visible, I think that the more salt in the mixture, the more visible and larger the DNA strands will be.) is correct as the more salt in the mixture the thicker the width of the DNA strand (average) is. Evaluation: I think overall our method is acceptable but it is not the best, next time if I do this experiment again I think the independent variable will be the amount of detergent and soap mixture instead of only salt. This experiment is to test how useful and how the salt effects the results of the experiment. (The visibility of the DNA)

Evaluation-suggested improvements: I think that the math it could be improved by controlling the salt and detergent mixture instead of just controlling one variable in the mixture I feel like that would make it more valid. Overall I think our experiment is quite reliable as we did a very detailed variables and we also repeated the experiments five times. We used the ruler to record the results and I feel that is not very precise as lifting both the ruler and they test tube up together, they might not be on the same level when measuring that human error is easily made and it may not be as precise. Bibliography: "Activities: Classroom Activities in Plant Biotechnology." Activity 1. N.p., n.d. Web. 13 Sept. 2016. "DNA Evidence." : How It’s Done. N.p., n.d. Web. 13 Sept. 2016. "Extracting DNA from Living Things." Nuffield Foundation |. N.p., n.d. Web. 27 Sept. 2016. "How Are Genetic Conditions Treated or Managed? - Genetics Home Reference." U.S National Library of Medicine. U.S. National Library of Medicine, n.d. Web. 13 Sept. 2016. Website "Importance of Being Able to Extract DNA?" Yahoo! Answers. Yahoo!, n.d. Web. 13 Sept. 2016. Jayden, Shizuko Ziglar, Connie, Marie Jonas, Carl, Demi, Kathleen, Mandy, M., Jordan, T., Noriae, A., #biofreak!, and Student. "Carl." Science Cafe. N.p., 22 Dec. 2008. Web. 13 Sept. 2016. "Strawberry DNA - Food Science - The Lab." The Lab. Steve Spangler Science, n.d. Web. 13 Sept. 2016. "Variables in Your Science Fair Project." Science Buddies. N.p., n.d. Web. 16 Sept. 2016.