Safety Rules Reminders

Transcription

1 Safety Rules Reminders 1. Take your time doing your experiment. 2. Wash your hands when the class ends. 3. No horseplay, but it s ok to have fun. 4. No cell phones, put away phone and ear buds. 5. Know where safety items are located. 6. Don t leave chemicals unattended. 7. Dispose of waste properly. 8. Be gentle with our instruments. 9. Use instruments properly. 10. Clear floor area. 11. Respect peers and teachers. 12. Read lab before class. 13. Wear only closed toe shoes.

2 Safety Rules Reminders 1. Respect the equipment. Use them properly. 2. Don t touch anything unless asked to do so. 3. Use common sense when working. 4. Tie back long hair. 5. Listen to the teacher. 6. Don t taste anything. Go to the hallway to eat or drink. 7. Don t smell anything directly. 8. Personal belongings go under the table. 9. Phones away! 10. Dispose of waste appropriately. 11. Respect others and help your lab partners.

3 Lab Norms & Reminders 1. Safety

4 What is Agarose Gel Electrophoresis? Slides to accompany Food Dye Electrophoresis unit

5 2QVb88&index=1&list=PLUnALhV4nXxP9x7QOws79_12-tSkblNG6 From: 4:09-4:18; repeat On your prelab worksheet page 2: Write down: I notice I wonder:

6 Draw a model Make up a hypothesis of: Why are the colors moving towards a different direction? or Why are colors not moving towards the same direction? Draw a model of hypothesis on the pre-lab activity sheet, page 2

7 Jigsaw Reading Read silently for 1-2 minutes, independently. Reading #1 Electrophoresis is a versatile tool in molecular biology. There are many different types of electrophoresis but they all work on the same principle. Samples are places on one end of a gel. The gel is a substance that consists of a molecular matrix of evenly sized and spaced openings. An electrical current is passed through the gel. The current moves the molecules in the sample through the gel. The rate at which the molecules move depends on both their size and their charge. Large molecules will be slowed by the matrix while small molecules will move more quickly. Molecules with a charge will move rapidly while uncharged molecules will move slowly.

8 Jigsaw Reading Read silently for 1-2 minutes, independently. Reading #2 Gel Electrophoresis: The process in which molecules (such as proteins, DNA, or RNA fragments) can be separated according to size and electrical charge by applying an electric current to them while that are in a gel. The current forces the molecules through pores in a thin layer of gel, a firm jelly-like substance. The gel can be made so that its pores are just the right dimensions for separating molecules within a specific range of sizes and shapes. Smaller fragments usually travel further that larger ones.

9 Jigsaw Reading Read silently for 1-2 minutes, independently. Reading #3 Gel electrophoresis is a laboratory method used to separate molecules according to size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores. The molecules travel through the pores in the gel at a speed that is inversely related to their lengths. This means that a small DNA molecule will travel a greater distance through the gel than will a larger DNA molecule. After just a few minutes, but mixture will start to separate.

10 Jigsaw Reading Answer the question on your pre-lab, page 2 How does electrophoresis separate molecules? Revise your hypothesis by revising your model (drawing).

11 What is Agarose Gel Electrophoresis? Slides to accompany Food Dye Electrophoresis unit

12 Agarose Gel Agarose is made from seaweed (agar-agar) It is a sugar or a polysaccharide It is similar to gelatin (Jell-O) It forms pores that molecules can go through -Coins-ALmond-Gelatin- Dessert/dp/B Q Image from:

13 Agarose Gel in Science In science, we use it to separate charged large molecules Today, we will separate food dye molecules Next time, we will use it to separate another large molecule, DNA Image from: Image from: Y.Loh Image from: babec.org

14 Agarose Gel Electrophoresis Movement of molecules Molecules move based on charge Separation on the agarose gel is based on size Think of this like a bear and rabbit moving through a forest

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17 Movement based on charge Charged molecules move through a gel when connected to electrical current One end of the gel is positively charged, and the other is negatively charged

18 What does a charged molecule look like? This is a charged molecule. What is its charge? Like charges repel; opposite charges Towards which end will this molecule migrate or move?

19 Movement based on size Smaller molecules move through the gel more quicker and travel farther. Larger fragments move slower and won t travel as far from the starting point (the well). As a result, the molecules are separated by size. In this gel below, which color: Travelled the farthest (from the well?) Is the biggest molecule? Wells _ +

20 Let s Predict Dye Cards Looking at dye cards, predict Which way (-) or (+) the molecules will travel? Which will travel farthest in each direction? Give reason or why for each molecule Write on your pre-lab, page 3

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22 Whole class, put your heads together and predict 1. Which end will each molecule move towards (+) or (-)? 2. How far from the well? Relative to each other?

23 Loading a well on a gel Micropipettor a review

24 How to load a gel Practice pipetting colored dye into wells 1. Use a P20 micropipette. 2. Set micropipette to 15µL. 3. Push the plunger to the first stop and keep it there before lowering the tip into the dye. 4. Slowly release the plunger to draw up 15µL of dye. 5. Put your elbows on the lab bench and steady the pipette over the well. Use your second hand to support your pipetting hand or arm.

25 How to load a gel Practice pipetting colored dye into wells 6. Lower the tip of the pipette under the surface of the buffer directly over the well. Avoid puncturing the bottom of the gel. 7. Gently depress the plunger to the first stop only to slowly expel the loading dye into the well. If the tip of the micropipette is centered over the well, the dye will sink to the bottom of the well. 8. Keep the pipette plunger depressed until the pipet tip is out of the gel box. This prevents the dye from returning into the tip!

26 Load Food dye on gel While gel is running, answer questions on: Page 4 Page 6

27 Skittles Dye Extraction Load on gel Follow the directions on page 8 Ask for help if needed Load gel with Skittles colors, share with students across bench Finish questions on page 7 and page 8 When done, clean up!