Text 100 Lab 5-Isolating Strawberry DNA Lab

Background/ Introduction

What does DNA stand for

DNA stands for deoxyribonucleic acid. DNA is a long molecule in the shape of a double helix - two spirals twisting around each other. These spirals are the backbone of the DNA, and are made up of sugars and phosphates. The spirals are connected by chemicals known as bases, which stretch between the spirals like the rungs of a ladder. DNA has four types of bases: adenine (A), thymine (T), guanine (G) and cytosine (C). A and T always join together, as do G and C.

What does DNA do?

Our genes are made up of DNA, and DNA contains our unique genetic code. Like a recipe book or instructions for lego , DNA holds the instructions for making all our proteins, which do all the jobs in our bodies.

How much DNA do you share with these living things?

You don’t look much like a fly or a worm. But, believe it or not, you share genes with both of them and with every other living thing. Scientists study the genes in bacteria, zebrafish, and other living things to learn more about humans

Chart showing DNA percent similarity to humans.

In today’s lab activity, you will be extracting DNA from a strawberry. You will be performing the lab while filming yourself with your phone.

You will be adding a buffer solution made with soap and salt to the strawberry cells. The soap from the buffer solution disrupts the cell membrane’s phospholipid bilayer and releases the cellular components into the buffer. The salt in the buffer binds to the negatively charged phosphate groups of DNA’s sugar-phosphate backbone, shielding some of the negatively charged areas of the DNA. It is this shielding which allows the DNA molecules to loosely bind together. The DNA will then be extracted.

Methods

Please write down the methods that you used to isolate the strawberry DNA in your lab notebook. The methods can be found at this link> Method for at-home strawberry DNA isolation

Results

Please write down the results you found. Quantitative and qualitative descriptions should be included. Please draw or take pictures of your results.

Discussion

Please answer the following questions in your lab notebook:

Describe the DNA collected during the spooling process. (Mark down how it appears, and its texture.)
What cell components were filtered out when you poured the pureed strawberries/buffer mixture through the coffee filter paper? Hint: Where can you find the DNA molecule? What makes up a plant cell?
What other surface do you think the DNA would stick to? Use the remaining DNA mass and try different surfaces.
Reflection

What’s the purpose for this laboratory?

What issues or problems did you have today?

Did anyone help you with this lab at home?

What evidence or data are given that help make this experience worthwhile?

What are some of the real-world complexities we should consider?

Which set of data or information is most relevant or important?

Has your perspective on the natural world changed, if so, how?
This lab you will write up for a formal lab report. Please use the lab report template for your lab report and be ready to discuss next week on the 27th of October when we meet next week to go over what everyone has done and written before you all submit next Monday night the 27th. Go to work and have fun! Can't wait to see your video clips!