The Characteristics of
Model Organisms
Lab Manual—2b
Plan for Lab
Tues. (1 hr early)—Duffy will start yeast broth
Tuesday—Finish Lecture, Parts I, II & III
Wednesday—FIRE, Part IV
Thursday—repeat Part IV/start write-up
Model Organisms
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Relatively easy to grow and maintain in a restricted
space
Relatively easy to provide necessary nutrients for
growth
Relatively short generation time
(birthreproductionbirth)
Relatively well understood growth and development
Closely resemble others organisms or systems
Examples
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Animal Kingdom—rats, mice (lots of offspring
is a +)
Bacteria—Escherichia coli (E. coli)prokaryotes
Fungal—Aspergillus (mold)--eukaryotes
Yeast—Saccharomyces cerevisiae
Lab Write-up
Purpose
Materials
Safety Precautions
Procedures
Data Collection & Analysis (table 2.3—add 8C, only 2
trials to average)
Conclusion (aka Data Analysis)
REE-results, evidence, explanation
PE—possible error
PA—practical applications
Thinking Like a Biotechnician
Background of Purpose
To grow and study an organism in a
laboratory, one should know the
environmental preferences of the species.
Maintaining an organism at less than optimal
light intensity, temperature, or oxygen level,
from example, may put the organism under
stress, possibly affecting its growth or other
processes.
Purpose
What are the temperature preferences shown
by three model organisms (E. coli,
Aspergillus niger and baker’s yeast) grown in
a biotechnology lab?
Prep. For Lab 2B
Month Prior
 Check supplies: bleach, petri dishes, LB base,
inoculating loops, 3 incubators, yeast, glucose, foil
 Order: E. coli, Aspergillus, Potato plates
Week Prior
 Perez will prepare LB agar & broth
 Pour plate (2 per group20)
 Set incubators at 30, 37 and 42 C
 Scalpels from other room
1 day prior
 make bacteria culture
Pre-lab—Plate Pouring
Pour LB agar base plates (Luria-Bertani )
E. Coli plate—use the LB agar with sterile
technique, use a 10ml pipette to transfer
10ml into a sterile plate
Yeast plate—use the LB* agar, sterile
technique, transfer 10ml using a pippet
*we are not using Malt extract agar because we
do not have it, but LB agar should have
enough nutrients to grow yeast
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Each group does 1 plate of each organism at their
assigned Temperature—wrap in foil for dark
1.
2.
3.
4.
5.
6.
7.
8.
9.
room
room
30C
30C
37C
37C
42C
42C
8C (instead of the suggested 4C)—please do 2
sets
Part I Tips
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Label the bottom
Inoculating loop
Triple Z streaking method
Close lids with tape
Make sure to use plate with LB agar
Part II Tips
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Each group gets one plate instead of a tube
of potato dextrose agar
We are using a potato dextrose agar plate
NOT tube
Cut aspergillus from stock plate—will be in
the hood
Put the aspergillus (fungi) on the plate fungi
side down to the agar and close the lid
Part III Tips
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Label the bottom
Inoculating loop
Triple Z streaking method
Close lids with tape
Make sure to use plate with LB agar
Part IV—Data Collection &
Analysis
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Make sure to come in at FIRE on Wednesday to do
a table like 2.3 (add space for 8C)
We will repeat the table again on Friday in class
This will provide us with more information of what
happens over time as well as temperature
The growth is exponential, but when nutrients run
out, they go into the death phrase (smelly!), we want
to try to catch them at their peak
Use results from all the groups posted on the
internet for you data
Tutorials
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Media Prep. (13)
LB Agar and Broth (14)
Sterile technique (15)
Pouring Plates (16)
Starting a Broth (18)
Streak Colonies (17)