2020(S11) Lecture:week 3

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=<center>Week 3 Tuesday </center>=
=<center>Week 3 Tuesday </center>=
==<font color = blue>ColiRoids </font color>==
==<font color = blue>ColiRoids </font color>==
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===Bacteria as pixels===
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''E. coli'' do not normally respond to light but [http://www.nature.com/nature/journal/v438/n7067/full/nature04405.html a recent publication ] describes a combination of genes that lead to light-responsive expression of β-galactosidase in ''E. coli.'' Recall from your study of the lac operon in biology classes that β-galactosidase is an enzyme encoded by the LacZ gene. Normally the protein cleaves the disaccharide, lactose, into two monosaccharides, galactose and glucose. 
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For the bacterial photography system, the "coliroid" cells producing LacZ cleave an indicator compound, giving rise to a black precipitate. When the cells are grown in the dark, transcription of LacZ is high and the indicator in the media turns black. When the cells are grown in the light, there is very little transcription of the LacZ gene and the media’s natural color (yellowish) shows through.
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[[Image:300px-Lactose etc.png|thumb|left| natural substrates and products for β-galactosidase]]
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[[Image:Redskins.jpg|thumb|right| "coli-roid" example]]
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For today, you can get use to this system with a few simple tests. You’ll plate a layer of cells on indicator medium in two dishes, and then incubate one dish in the light and the other in the dark until next time. You expect the dark-grown plate to turn a dark color and the light-grown plate to stay light. Y
==<font color = blue>Why are we doing this?</font color>==
==<font color = blue>Why are we doing this?</font color>==
=<center>Week 3 Studio</center>=
=<center>Week 3 Studio</center>=

Revision as of 12:05, 31 January 2011

Contents

Week 3 Tuesday

ColiRoids

Bacteria as pixels

E. coli do not normally respond to light but a recent publication describes a combination of genes that lead to light-responsive expression of β-galactosidase in E. coli. Recall from your study of the lac operon in biology classes that β-galactosidase is an enzyme encoded by the LacZ gene. Normally the protein cleaves the disaccharide, lactose, into two monosaccharides, galactose and glucose.

For the bacterial photography system, the "coliroid" cells producing LacZ cleave an indicator compound, giving rise to a black precipitate. When the cells are grown in the dark, transcription of LacZ is high and the indicator in the media turns black. When the cells are grown in the light, there is very little transcription of the LacZ gene and the media’s natural color (yellowish) shows through.

natural substrates and products for β-galactosidase
natural substrates and products for β-galactosidase
"coli-roid" example
"coli-roid" example

For today, you can get use to this system with a few simple tests. You’ll plate a layer of cells on indicator medium in two dishes, and then incubate one dish in the light and the other in the dark until next time. You expect the dark-grown plate to turn a dark color and the light-grown plate to stay light. Y

Why are we doing this?

Week 3 Studio

Homework

Week 3 Thursday

Getting to 3 ideas

We will not meet as a class today but you are expected to spend the 1.5 hours that you might have enjoyed in 26-152 looking at the requirements for the upcoming 3-Ideas Presentations and planning a project for which you can articulate at least 3 of these 5 points:

  1. What: what problem or opportunity are you thinking of focusing on? How sweeping or focused is this idea?
  2. How: what approach could you take to make a dent in the problem?
  3. What if if your project is fully successful, how big a difference could it make? what concerns does it raise?
  4. What else are there other technologies that can be used/have been used to address this area?
  5. Dunno how big are the gaps in what you know? how much is completely unknown or unknowable?
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