Tuesday 12th September 2023
Experiment 1: Working with Small Volumes
Aim of the experiment
The aim of this experiment is to get used to pipetting small volumes of liquid in the lab. A
series of different dilutions will be made with different volumes of the concentrated dye
Methyl blue (2 mg/mL) and water into cuvettes. The absorbance of these dilutions will be
measured using a spectrophotometer and plotted into a graph.
Hypothesis
The graph of various amounts of Methyl blue versus the absorbance at 620 nm in the
spectrophotometer gives a straight line.
Materials and Methods
● A tube of Methyl
● 11 plastic cuvettes
● Micropipette P20
● Micropipette P200
● Micropipette P1000
● Micropipette tips (yellow and blue)
● Water
● Spectrophotometer
All the steps of the Protocol of experiment 1 in the Lab Manual were followed.
1. Firstly, we calculated the amount of water per cuvette that was needed for a total
volume of 1000 µL. We also converted the Methyl Blue in µl to µg. This can be seen
in Table 2 in the second and fourth column.
Table 2. Table used for diluting Methyl blue into cuvettes
Methyl blue volume Water volume (µL) Total volume μg of Methyl blue in
(µL) cuvette
2 µL 998 1000 4
5 µL 995 1000 10
10 µL 990 1000 20
15 µL 985 1000 30
25 µL 975 1000 50
2. We pipetted the water volumes (shown in column 2), and added it to the 5 cuvettes.
This was done in twofold, so with a total amount of 10 cuvettes. We added the
volumes with a micropipette P1000.
3. After adding the water volumes, Methyl blue was added in the associated cuvettes.
The Methyl blue volumes of 2 µL, 5 µL, 10 µL and 15 µL were pipetted with a
Experiment 1: Working with Small Volumes
Aim of the experiment
The aim of this experiment is to get used to pipetting small volumes of liquid in the lab. A
series of different dilutions will be made with different volumes of the concentrated dye
Methyl blue (2 mg/mL) and water into cuvettes. The absorbance of these dilutions will be
measured using a spectrophotometer and plotted into a graph.
Hypothesis
The graph of various amounts of Methyl blue versus the absorbance at 620 nm in the
spectrophotometer gives a straight line.
Materials and Methods
● A tube of Methyl
● 11 plastic cuvettes
● Micropipette P20
● Micropipette P200
● Micropipette P1000
● Micropipette tips (yellow and blue)
● Water
● Spectrophotometer
All the steps of the Protocol of experiment 1 in the Lab Manual were followed.
1. Firstly, we calculated the amount of water per cuvette that was needed for a total
volume of 1000 µL. We also converted the Methyl Blue in µl to µg. This can be seen
in Table 2 in the second and fourth column.
Table 2. Table used for diluting Methyl blue into cuvettes
Methyl blue volume Water volume (µL) Total volume μg of Methyl blue in
(µL) cuvette
2 µL 998 1000 4
5 µL 995 1000 10
10 µL 990 1000 20
15 µL 985 1000 30
25 µL 975 1000 50
2. We pipetted the water volumes (shown in column 2), and added it to the 5 cuvettes.
This was done in twofold, so with a total amount of 10 cuvettes. We added the
volumes with a micropipette P1000.
3. After adding the water volumes, Methyl blue was added in the associated cuvettes.
The Methyl blue volumes of 2 µL, 5 µL, 10 µL and 15 µL were pipetted with a
