Journal of Academic Development and Education JADE Issue 9 | Page 28

28 | JADE
ARTICLE #2 | 29
L. A. ROBINSONNAY ÖZEN
TRI-HARD PIPETTING:
DEMONSTRATING PIPETTING ACCURACY USING DIE HARD WITH A VENGEANCE
Example student
transfer Number of actions Simplest solution Number of actions
400µl from 2ml
to 0.5ml 2 500µl from 2ml
to 1.5ml 3
100µl from 2ml
to 1.5ml 1 600µl from 1.5ml
to 2ml 3
200µl from 1.5ml
to 2ml 1 200µl from 1.5ml
to 0.5ml 1
400µl from
0.5ml to 2ml 2 200µl from 1.5ml
to 0.5ml 1
Table 1: Comparison of transfer methods
Figure 1: Instructions provided to students
of the class who will weigh the tubes. All measurements are read out
and recorded on the whiteboard with a simple tick or cross next to
each measurement depending on whether it falls inside or outside
the accepted error rate. The top three attempts are also ranked to
give 1 st , 2 nd , and 3 rd place in a mini-leaderboard. Leaderboards are a
core gamification element and although their effectiveness has been
debated, it is used here as a short term demonstration of ‘success’
and does not rank the whole class, therefore no student is ranked
‘bottom of the class’. In addition, names are not used: students are
just aware of which line of results is theirs.
It has been seen on each year of delivery of Tri-Hard Pipetting that
students greatly enjoy the exercise and all are willing to try and
solve the problem. It is rare that when walking around the room
students are distracted by other activities or simply not taking part.
The key benefits to this exercise beyond accurate pipette use are
the three skills which are the basis of Tri-Hard Pipetting: Teamwork,
Forethought, and Precision (Figure 2). Students work together to
solve the problem and then carry out the solution as accurately as
possible in order to obtain the correct volumes/weights.
Results
There are multiple ways in which this problem can be solved but it has
been found over three years of delivery of this exercise that students
have a tendency to over-complicate the problem and the resulting
increase in transfer between tubes begins to introduce further error.
It is also often seen that students lose track of their transfers and
therefore the solution may be correct but the execution is incorrect.
The simplest solution to this problem is to place all of the material
into the 1.5ml tube and pipette out 600µl and 200µl respectively.
The variation between the simplest solution and an example student
answer is shown in Table 1.
Figure 2: The Tri-Hard Skills
Once all tubes have been used, the class is then drawn back to
attention and volunteers of the successful attempts are asked to
read out their solutions to the class, which are often similar to that
shown in Table 1. Only 3-4 groups per year will identify the simple
solution to the problem and often these groups will approach
a member of staff as they feel it’s too simple. The ‘KISS’ principle
(keep it simple, stupid) and Occam’s Razor is introduced to the class
and the simple solution presented to them; it is always met by a
brief silence then talk between students about how they could have
missed it. Another key aspect is then highlighted to students; that