biology lab
lulsab
prelab_2-_molec._techniques.docx
Name:_______________________
Date:__________
Pre-lab 2: Molecular Biology Lab Techniques
Read through the lab procedures, watch the three associated videos, and then answer the following questions.
1. According to the explanation of the volume display of a 2-20 μL pipette during the first pipetting video, write the volume (and units) of the following readouts:
|
0 |
|
1 |
|
2 |
|
|
2 |
|
7 |
|
9 |
|
|
5 |
_______ |
0 |
_______ |
7 |
_______ |
Do you notice a problem with any of the above volumes? Explain.
2. What were three mistakes that the lab technician made while pipetting in the second video?
3. Which end of the electrophoresis chamber (positive or negative electrode) does the DNA migrate towards during electrophoresis? Why?
4. Which size fragments of DNA migrate through the gel most quickly, larger or smaller? Why?
5. What is a DNA Ladder?
6. Why should gloves be worn whenever handling ethidium bromide, or anything that contains or was in contact with ethidium bromide?
7. What is the purpose of each temperature setting (94, 50, 72 in our procedures) during a PCR procedure?
8. Explain how only 25 or 30 cycles within a PCR thermocycler can produce over a billion copies of a desired DNA fragment.
