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Transformation of E.coli with pGLO. Dan Prochaska and Jeff Winslow Talawanda/Butler Tech. Purpose. Challenge students to participate in cutting edge laboratory activities that emphasize important skills carried out in a structured environment.
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Transformation of E.coli with pGLO Dan Prochaska and Jeff Winslow Talawanda/Butler Tech
Purpose • Challenge students to participate in cutting edge laboratory activities that emphasize important skills carried out in a structured environment. • To make connections to modern commercially viable protocols, i.e. human insulin production.
Lesson Plan • Three day lesson. • Day 1: Powerpoint introduction, handouts with protocol, streaking starter plates, and pre-assessment • Day 2: Complete transformation protocol, student groups make predictions about results • Day 3: Observe plates using U.V. pen lights and record observations. Make connections to real world applications. Complete post assessments.
pGLO lab. Objectives • Transform E. coli host cells with plasmid DNA. • Predict the results on selective agar plates. • Observe and record actual plate data. • Draw conclusions from the experiment and list possible sources of error.
Introduction What is genetic transformation? • When host bacteria acquire novel traits that are encoded in genes contained on plasmid, (pGLO) DNA. What new traits will E.coli acquire from the transformation? Antibiotic resistance (ampicillin) Green Fluorescence: Where did this trait come from?
What is the source of green flourescence? • The marine jellyfish Aequorea victoria
Plasmid DNA • Very small (103bp) piece of circular DNA • Replicates autonomously, (ori site). • Is in addition to the large (106bp) E. coli chromosome. • Can be exchanged between cells. • Carries important genes for traits such as antibiotic resistance. • In this laboratory we are investigating ampicillin resistance.
Plasmid DNA A small circular piece of DNA that is naturally occurring in some bacteria. It can be exchanged between cells and often carries antibiotic resistance genes
pGLO plasmid genes • GFP gene encodes a green fluorescent protein (GFP) • Bla gene encodes the enzyme beta lactamase that degrades the antibiotic ampicillin thus, protecting the cell from its harmful effects. • AraC is a regulatory gene that encodes a protein that acts like a switch that turns on the expression of the GFP gene.
Transformation- Terms • Competence: cells are able to take up a plasmid from their surroundings • How do we make our E.coli cells competent? • Gene expression: cells replicate, transcribe, and translate genes located on the pGLO plasmid
Transformation Cell wall GFP Bacterial chromosomal DNA Beta lactamase (ampicillin resistance) pGLO plasmids