Biogen Idec Community Laboratory
Micropipet Practice
Introduction:
Molecular biologists and genetic engineers work with such small
quantities that special tools had to be developed to ensure accurate
measurements. One of these tools is the micropipet, which is a very
common tool in biotechnology.
This investigation will teach you how to use the micropipet so that you
will be able to carry out today’s lab, which involves critical
measurements using a special unit of measure called the microliter
(μl).
You already know that 1 liter (l) equals 1,000 milliliters (ml). So,
if a typical bottle of soda holds 2 liters (l), then that equals 2,000
milliliters (ml). A microliter (μl) is so small that it takes 1 million
microliters (μl) to equal 1 liter (l). That means that the same
2- liter (l) soda bottle would equal 2,000,000 microliters (μl)!!!
= 2 liters (l)
= 2,000 milliliters (ml)
= 2,000,000 microliters (μl)
Here are different types of micropipets, how much they each measure, and how each window
setting reads:

p200 micropipet measures from 21 μl to 200 μl.
NOTE: The label on the control button for this micropipet says it measures from
50 μl to 200 μl, but you can measure as low as 21 μl with this micropipet.
Example window setting:
1
150 μl=
5
0

p20 micropipet measures from 2.5 μl to 20 μl.
NOTE: The bottom window, which is red, means this number indicates 0.10 of a μl.
Example window setting:
12 μl=
1
2
0

p10 micropipet measures from 0.5 μl to 10 μl.
NOTE: The bottom window, which is red, means this number indicates 0.10 of a μl.
Example window setting:
5μ l=
0
5
0
Adapated from:
CityLab, Boston, MA
Lawrence Livermore National Labs, Livermore, CA
1
10/03/05
Biogen Idec Community Laboratory
Micropipet Practice
You will be doing lots of micropipetting in the Community Lab. Much of it will be in very small
amounts, such as 1 μl. The success of your lab experiments is highly dependent on your
micropipetting accuracy.
Follow the instructions below. For each step, choose the correct micropipet to measure the
amount indicated into your collection tube. Watch carefully as you add the solutions and note any
observations to the solution.
1. Watch and listen carefully as the instructor will talk you through how to properly use a
micropipet.
2. Obtain a tube of colored solution.
3. Obtain an empty 1.5 ml microcentrifuge tube. This is your collection tube. You will be making
six different measurements and collecting them all together in this collection tube.
4. Fill in the data table below by writing in which micropipette is correct to use for that
measurement and what the window setting reads. Be sure to check off the boxes as you
complete each measurement.
EXAMPLE
Measure
20
ul into your collection tube
Micropipet
Type
P20
Window
Setting
2
0
0


PRACTICE
Measure
a)
200
ul into your collection tube
b)
25
ul into your collection tube
c)
14
ul into your collection tube
d)
1
ul into your collection tube
Micropipet
Type
Window
Setting

5. What should be the final volume in your collection tube? ___________
(To calculate, add up the ul listed in the table above.)
Adapated from:
CityLab, Boston, MA
Lawrence Livermore National Labs, Livermore, CA
2
10/03/05
Biogen Idec Community Laboratory
Checking your micropipetting accuracy:
6. What is the correct micropipet to collect the final volume you micropipetted into your
collection tube? ____________
(This is the final volume you calculated in 5. above.)
7. Use the micropipet identified in 6. above to draw up the solution in your collection tube.
If you did your micropipetting correctly, you should not have any liquid left in the
collection tube, nor any bubbles in your pipet tip.
8. What are your observations?
9. Based on your observations from 8, was your actual final volume more or less than you
thought?
Adapated from:
CityLab, Boston, MA
Lawrence Livermore National Labs, Livermore, CA
3
10/03/05