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

Relatively easy to grow and maintain in a restricted space

Relatively easy to provide necessary nutrients for growth

Relatively short generation time (birthreproductionbirth)

Relatively well understood growth and development Closely resemble others organisms or systems

Examples

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

PurposeMaterialsSafety PrecautionsProceduresData Collection & Analysis (table 2.3—add 8C, only 2

trials to average)Conclusion (aka Data Analysis)

REE-results, evidence, explanationPE—possible errorPA—practical applications

Thinking Like a Biotechnician

Background of Purpose

To grow and study an organism in alaboratory, one should know theenvironmental preferences of the species. Maintaining an organism at less than optimallight intensity, temperature, or oxygen level,from example, may put the organism understress, possibly affecting its growth or otherprocesses.

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 group20) Set incubators at 30, 37 and 42 C Scalpels from other room1 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

Each group does 1 plate of each organism at their assigned Temperature—wrap in foil for dark

1. room2. room3. 30C4. 30C5. 37C6. 37C7. 42C8. 42C9. 8C (instead of the suggested 4C)—please do 2

sets

Part I Tips

Label the bottom Inoculating loop Triple Z streaking method Close lids with tape Make sure to use plate with LB agar

Part II Tips

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

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

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

Media Prep. (13) LB Agar and Broth (14) Sterile technique (15) Pouring Plates (16) Starting a Broth (18) Streak Colonies (17)