Locomotion Lab Notebook (ELN 6)
Instructions
- Lab notebooks are completed digitally using the Crowdmark platform. You will submit your lab notebook before the end of the lab time.
- The amount of work expected for these lab notebooks is reflective of the time available! Labs run for 3 hours – we have therefore designed the lab activities and the lab notebook prompts in such a way that they will be able to be completed within the 3 hour window of provided time.
- It is strongly advised that you read the lab outline BEFORE the lab starts to ensure you will be prepared to manage your time effectively and complete all protocols during the lab.
- This lab notebook will be completed as PAIRS
- This lab notebook (and completion of the lab) is pass/fail
- Assignment Deadlines
- Policies on Submitting Work, Absences and Missed Work
- Specifications guidelines for Electronic Lab Notebooks
Part 1: Pre-lab
- What is the purpose of today’s lab activity?
- What protocols will you be completing in the lab?
- Are there any safety precautions to be aware of before starting?
- Read the Preparing Chemical Solutions Appendix
- You are going to work with a prepared solution of M9 buffer in the lab this week. The solution was prepared for you, but it is an important skill to be able to prepare solutions in the lab. This is a skill you learned last year in Chemistry 1A03/1AA3, and this appendix reviews the theory.
There are several different reagents within M9 buffer. The recipe we use for a final volume of 1 L of M9 buffer is shown below, in units of moles per litre of liquid:
- 0.042 mol/L of Na2HPO4-7H2O(s) (dibasic) – (molar mass of this compound = 268.07 g/mol)
- 0.022 mol/L of KH2PO4(s) (monobasic)
- 0.086 mol/L of NaCl(s)
- 1 ml of 1M MgSO4(l) solution (This 1 ml is when the desired amount of solution is 1 L. It will also scale with the solid reagents for different final volumes).
Table I: Desired volumes for your M9 buffer solution. You have been assigned ONE pair of values according to your pod letter.
| Desired Volume of M9 buffer (ml) | Pod Letter |
|---|---|
| 4500 | A/B |
| 3800 | C |
| 2700 | D |
| 3300 | E/F |
| 4200 | G |
| 2100 | H |
- What is the molar mass of KH2PO4? What is the molar mass of NaCl?
- Show all of your calculations and describe how to prepare your M9 buffer solution. Indicate the weight (g) of each of the 3 solid reagents you will be using, as well as the volume of 1M MgSO4 solution that you would need and the steps you would follow in the lab to create this final product. This is not meant to be a giant written answer – this question is just a pre-lab calculation.
Part 2: Experimental Design
- What type(s) of replicates were used for each of the two experiments today? (i.e. Technical or Biological)
- What is the hypothesis/prediction for each of the two experiments/assays? (i.e. what are we expecting we will see when we analyze the class data set?)
- What is the independent variable? (Was it something intrinsic to the organisms, or was it something related to the procedure we executed?)
- HINT: the independent variable is the thing that changes between treatment groups
- What is the dependent variable? (Note: there are two, since there were two experiments with different measured endpoints!)
Part 3: Figure 1
- Prepare a multi-panel figure presenting the quantitative findings from the thrashing assay and the touch-test for your entire lab section.
- You will use the class data set completed during lab time. This means you will include data for all 3 mutant strains of nematodes (Q24, Q35, Q40).
- It is up to you to decide which type(s) of figures are the most effective for presenting your findings for each of the two experiments completed.
- Think back to the types of figures you’ve tried so far in the past assignments – which do you think will best represent the two types of data collected in the two experiments?
- The touch test resulted in a score
- The thrashing assay was based on body thrashes/unit time
- Think about the units you’ll use to present this data – recall other types of units you’ve used for previous assignments
- Remember the important parts of figures you have been practicing (e.g., captions, labels/legends, error indicators, etc.)
- Think back to the types of figures you’ve tried so far in the past assignments – which do you think will best represent the two types of data collected in the two experiments?
Refer to the ‘Results: Figures and Tables‘ section of the lab report writing guide for details on how to prepare a figure and caption
- Click for an example of a figure of a graph
- Remember – a figure includes both the image and a caption!