Measuring large and small volumes in the Biotech Lab
Purpose: Which instruments are best to used to measure specific volumes? How precisely can you measure using
each graduated cylinder (25mL, 250mL, 500mL, and 1000mL)? How precisely can you measure using a pipette
(1, 5 and 10mL)? How accurately can you prepare samples using each graduate and pipette?
Materials:
(You should be able to come up with this list on your own)
Procedure:
1. Using a permanent marker, label four empty 500L beakers with A, B, C, and D your initials and date.
2. Carefully, study each graduate and pipette available for use. What is the maximum amount that each graduated
cylinder and pipette can measure? What is the value of the smallest graduation on each pipette? For each
graduate, and pipette make sure you know what the maximum and minimum volumes are that each instrument
can hold and what each graduation represents.
3. Using the smallest graduate or pipette possible, measure the following dye solutions into each tube according
to the matrix shown in Table 3.1. (HINT: Add the smallest volume first. Add the next volume inside of the
beaker allowing it to flow down to the bottom). Give the beaker a gentle shake to mix the volumes.
4. Compare the beakers that you created to the “key” beakers provided by the instructor. These are the standards
for comparison. For each sample beaker, check the level of the final volume, the final color, and proper
labeling.
Table 3.1: Practicing with Pipettes and Graduates
Beaker
A
B
C
D
Solution 1 Solution 2 Solution 3 Solution 4
Solution 5
RED
YELLOW
BLUE
GREEN COLORLESS
6.3mL
0.5ml
263mL
22.4mL
102mL
24mL
10.8mL
0mL
303mL
8.3mL
4.0mL
1.5mL
2.4mL
0.3mL
412mL
35.5mL
205mL
0.7mL
115.4mL
1.4mL
5. If the volume of any beaker is not within one meniscus of the “KEY” beakers, it should be dumped out and
remade.
6. Keep track of your attempts to create sample beakers in the “Observation” section of your lab notebooks.
7. In your “Observations” section, be sure to record what instruments you used to make each of your trial samples
(example: for 105mL I used the 100mL graduate and the 5mL pipette)
Reflection and Analysis
1. For volumes between .01mL and 10mL, explain which pipette and which pump are appropriate to use for
measuring and dispensing. (Be sure to give the ranges for all of the pipettes)
2. For volumes between 10mL and 1000mL explain which graduated cylinders are appropriate to use for
measuring and dispensing. (Be sure to give the ranges for all of the graduated cylinders that you could use if all
were available).
3. Based on your experience in preparing the samples, what can be done to improve your accuracy and precision
in preparing the samples?
Beaker
Solution 1
RED
Solution 2
YELLOW
Solution 3
BLUE
Solution 4
GREEN
Solution 5
COLORLESS
A
6.3mL
0.5ml
263mL
22.4mL
102mL
(10mL pipette)
(1mL pipette)
(500mL graduate +
(20mL graduate +
(100mL graduate +
5mL Pipette)
5mL pipette)
5mL pipette)
260mL + 3mL
20mL+ 2.4 mL
100mL + 2mL
B
24mL
10.8mL
(25mL graduate)
(10mL +1mL
0mL
pipette)
303mL
8.3mL
(500mL graduate
(10mL pipette)
+5mL)
300mL + 3mL
C
D
4.0mL
1.5mL
2.4mL
0.3mL
412mL
(5mL pipette)
(1mL pipette)
(500mL graduate +
5mL pipette )
410+2 mL
115.4mL
1.4mL
(100mL pipette +
(5mL pipette)
(5mL pipette)
(5mLpipette)
35.5mL
205mL
0.7mL
(500mL graduate +
(1mL pipette)
(100mL graduate+
10mL Pipette)
30mL + 5.5mL
5mL pipette)
200mL + 5mL
1mL pipette)
115mL + .4mL