Subject: BIO365L Prelab 1 - Feedback on first draft
I have read through all of your prelab drafts, and there is good news and bad news. Because the good and bad news is the same for everyone, I’m sending a general email as feedback for this assignment.
First, the good news. All of you understand the basic issues behind this first lab module: the passive properties of neurons (resistance and capacitance). Moreover, everyone has strong basic writing skills. This lets us focus on the science and style, rather than the low-level mechanics of report writing. (Nothing sends shivers down my spine like sentences that don’t have verbs, for example.) Finally, all of you clearly took the assignment seriously and gave it your best effort. I really appreciate that. Thanks.
Now, the bad news. The bad news is entirely my responsibility. Your prelabs all covered the first exercises with the model cells, rather than the experiments that are the focus of this module. This is perfectly understandable, because that is all the information you had available the first day of class when I gave you the assignment. I simply didn’t explain the assignment in enough detail. I apologize for that.
What we are looking for here is a prelab that covers the actual experiments for the first module (Passive properties). So, rather than leading up to the exercises with the model cells, I want the prelabs to lead up to the experiments you will run on real cells.
As you all discovered Wednesday, patching neurons is difficult and time consuming. (Trust me, you will successfully patch on to cells, and it will happen soon!) Each time you get a cell online, the clock is ticking. You will have maybe 15-30 minutes to run the assigned experiments before the cell starts to give out on you. You won’t have time to read through the lab manual to figure out what to do next, so you will need to know what you are going to do, what kind of data you need, and why.
Therefore, the purpose of the prelab assignment is to ensure two things:
1. That you understand the core issues addressed in the lab module. In this case it is the passive properties of neurons. Be sure to focus on the passive properties of cells, and the consequences of those passive properties.
2. That you understand the experiments you will perform (e.g., what comparisons will you make, what will you manipulate, and what types of outcomes do you expect?). This way you will know what to do when the opportunity is present.
In revising your prelabs to accomplish these goals, I suggest taking this approach:
Make sure you review the entire lab manual for Module 1 (available on class website). (The handout we gave you on the first day of class is just the first part of that module.) Note statements that are underlined for emphasis, or preceded with statements like “The take home message.” These are core concepts central to this module. Then, read carefully the last three pages of the manual, where the specific experiments are described. We are looking for a prelab that covers these experiments. With this information in hand, you should be able to fully address the prelab’s questions.
In light of the confusion we caused on the first draft of the prelab, I am changing the due date for your final version of Prelab 1 to September 17 so that you have an extra week to work on it. Note that we will still have our first on Sept. 17th.
Don’t hesitate to email me if you have questions or need additional information/clarification about the assignment.- M