Wednesday, 22 september, 2021
Experiment 1: Working with small volumes
The aim of the experiment
The aim of the experiment is to learn how to use a (micro)pipette, because a (micro)pipette
is a very commonly used tool in the lab. During this experiment, we will learn how to use
three micropipettes, by practicing with three pipettes with different volume ranges. We will
also learn how to hold a pipette correctly and how to read the correct volume on the volume
indicator. After mastering the use of a (micro)pipette, we will need to make a series of
dilutions of the coloured compound; Methyl blue. The concentrations need to be maesured
afterwards, because we’ll need to plot the results in a graph. The graph will give us a good
representation of how accurate your pipetting is. The line fit of the points in the graph will
indicate how accurate our pipetting is. Thus, If your pipetting skills are good, the graph of
the amount of Methyl blue versus the absorbance in the spectrophotometer should give a
straight line.
Hypothesis
The graph of the amount of Methyl blue versus the absorbance in the spectrophotometer
should give a straight line if your pipetting skills are good. My hypothesis is that my pipetting
skills are good enough to produce a straight line in the graph. Therefore, I expect that my
line will be straight in the graph.
Material and Methods
(Material per person)
• A tube of Methyl blue solution (2mg/mL)
• 11 plastic cuvettes
• micropipette P20
• micropipette P200
• micropipette P1000
• micropipette tips (yellow and blue)
• water
• spectrophotometer
The given solution of Methyl blue is 2 miligrams per mililiter.
The given solution has a ratio of 2:1, so the converted solution of Methyl blue is:
2 micrograms per microliter (2 μg/μL).
Methyl blue volume Water volume (μL) Total volume (μL) μg of Methyl blue in
the cuvette
Experiment 1: Working with small volumes
The aim of the experiment
The aim of the experiment is to learn how to use a (micro)pipette, because a (micro)pipette
is a very commonly used tool in the lab. During this experiment, we will learn how to use
three micropipettes, by practicing with three pipettes with different volume ranges. We will
also learn how to hold a pipette correctly and how to read the correct volume on the volume
indicator. After mastering the use of a (micro)pipette, we will need to make a series of
dilutions of the coloured compound; Methyl blue. The concentrations need to be maesured
afterwards, because we’ll need to plot the results in a graph. The graph will give us a good
representation of how accurate your pipetting is. The line fit of the points in the graph will
indicate how accurate our pipetting is. Thus, If your pipetting skills are good, the graph of
the amount of Methyl blue versus the absorbance in the spectrophotometer should give a
straight line.
Hypothesis
The graph of the amount of Methyl blue versus the absorbance in the spectrophotometer
should give a straight line if your pipetting skills are good. My hypothesis is that my pipetting
skills are good enough to produce a straight line in the graph. Therefore, I expect that my
line will be straight in the graph.
Material and Methods
(Material per person)
• A tube of Methyl blue solution (2mg/mL)
• 11 plastic cuvettes
• micropipette P20
• micropipette P200
• micropipette P1000
• micropipette tips (yellow and blue)
• water
• spectrophotometer
The given solution of Methyl blue is 2 miligrams per mililiter.
The given solution has a ratio of 2:1, so the converted solution of Methyl blue is:
2 micrograms per microliter (2 μg/μL).
Methyl blue volume Water volume (μL) Total volume (μL) μg of Methyl blue in
the cuvette
