Team:ETH Zurich/modeling/diffmodel

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(Estimation of parameters from literature)
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=== Estimation of parameters from literature ===
=== Estimation of parameters from literature ===
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The initial number of beads is 10 million. According to Lars Müller's master thesis<sup>[[Team:ETH_Zurich/project/references|[29]]]</sup>, in picoliter beads, cells doubling time is 30 minutes. Here we are using beads with a volume in the microliter range. Because of bead volume, oxygen and nutrients are much less accessible. Therefore, we multiplied this doubling time by 4. We have a rgowth rate of 0.006 min<sup>-1</sup> which is still above the growth rate in anaerobic conditions (0.004 min<sup>-1</sup> according to [http://bionumbers.hms.harvard.edu/search.aspx?log=y&task=searchbytrmorg&trm=growth+rate+e+coli&org= Bionumbers]) )
The initial number of beads is 10 million. According to Lars Müller's master thesis<sup>[[Team:ETH_Zurich/project/references|[29]]]</sup>, in picoliter beads, cells doubling time is 30 minutes. Here we are using beads with a volume in the microliter range. Because of bead volume, oxygen and nutrients are much less accessible. Therefore, we multiplied this doubling time by 4. We have a rgowth rate of 0.006 min<sup>-1</sup> which is still above the growth rate in anaerobic conditions (0.004 min<sup>-1</sup> according to [http://bionumbers.hms.harvard.edu/search.aspx?log=y&task=searchbytrmorg&trm=growth+rate+e+coli&org= Bionumbers]) )
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Lars Müller also mentions in his master thesis<sup>[[Team:ETH_Zurich/project/references|[29]]]</sup> that the maximum capacity of his 34 pL beads is 3000 cells, which would correspond to  maximum of N<sub>m</sub> = 8. 10<sup>8</sup> cells per bead in our case (10 &mu;L beads).  
Lars Müller also mentions in his master thesis<sup>[[Team:ETH_Zurich/project/references|[29]]]</sup> that the maximum capacity of his 34 pL beads is 3000 cells, which would correspond to  maximum of N<sub>m</sub> = 8. 10<sup>8</sup> cells per bead in our case (10 &mu;L beads).  
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According to Kaplan's paper<sup>[[Team:ETH_Zurich/project/references|[28]]]</sup>, LuxAHL diffuses very fast through the membrane : ''"This report demonstrates that V. fischeri and E. coli are freely permeable to autoinducer. When autoinducer was added to cell suspensions, internal concentrations approximated external concentrations, and equilibration was rapid (within 20 s)."''
According to Kaplan's paper<sup>[[Team:ETH_Zurich/project/references|[28]]]</sup>, LuxAHL diffuses very fast through the membrane : ''"This report demonstrates that V. fischeri and E. coli are freely permeable to autoinducer. When autoinducer was added to cell suspensions, internal concentrations approximated external concentrations, and equilibration was rapid (within 20 s)."''
Therefore we take 100 min<sup>-1</sup> for D<sub>m</sub>, and indeed external and internal concentrations become very quickly almost equal.
Therefore we take 100 min<sup>-1</sup> for D<sub>m</sub>, and indeed external and internal concentrations become very quickly almost equal.
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Cbeads
Cbeads

Revision as of 17:47, 16 October 2014

iGEM ETH Zurich 2014