Acknowledgment: This assignment is based in part on Boedicker JQ, Vincent ME, Is

For This or a Similar Paper Click Here To Order Now

Acknowledgment: This assignment is based in part on Boedicker JQ, Vincent ME, Ismagilov RF. Microfluidic confinement of single cells of bacteria in small volumes initiates high-density behavior of quorum sensing and growth and reveals its variability. Angew Chem Int Ed Engl. 2009;48(32):5908-11. doi: 10.1002/anie.200901550. Feel free to read/skim this paper, but note that I have changed many of the details for the purposes of this assignment, and the details I provide for the assignment are fictitious/hypothetical (assuming…then…).
Background: Conventional dogma is that microbes use “quorum sensing” to determine if a certain threshold of other microbes of the same species are present; once this threshold is met, the microbes change their behavior. For example, some species of bacteria form biofilms when enough other bacteria of the same species are present. Microbes release chemical signals that let other microbes know that they are nearby. (The terminology “quorum sensing” is reminiscent of the concept of a “quorum” in some political institutions whereby enough people must be present for a vote or other official business to continue.) For more background, please see: https://en.wikipedia.org/wiki/Quorum_sensing#Mechanism and https://en.wikipedia.org/wiki/Autoinducer (or other literature).
Overview of the Design Project problem: Although quorum sensing has typically been thought of as a “group” behavior, your research group is interested in testing the hypothesis that it is merely dependent on the concentration of autoinducers (small molecules that initiate quorum sensing) around a bacterium. The overarching objective of this design project is to design an experiment to test the hypothesis that quorum sensing behavior can be observed in small populations (~1-20 bacterial cells) when they are confined in small volumes (paraphrased from Boedicker, 2009).
Fictitious/hypothetical details for this assignment: Assume that you will use model organism Bacteria xxx that produces Enzyme A only when quorum sensing behavior is initiated. You can purchase a fluorogenic substrate, Reagent Y, which is not fluorescent itself but becomes fluorescent when Enzyme A cleaves it (recall that we’ve talked about fluorogenic substrates in class, and they are also used in many papers cited in the droplet-based microfluidics review articles posted on Canvas). Your research group has preliminary data suggesting that when ~1-20 cells of Bacteria xxx are encapsulated into volumes of ~750 pL, quorum sensing behavior begins after ~12 h. Your group would like to gather more data (tens of thousands of droplets) to further test the overarching hypothesis; to achieve this you will use a droplet-based microfluidics approach. The aqueous phase (dispersed phase) will contain Bacteria xxx, and Reagent Y (aq) will be added. A fluorinated oil will be used for the continuous phase.
One quick reason “why we care”: One of the many reasons this problem is interesting is that some bacteria form biofilms as a result of quorum sensing. Biofilms cause significant problems across numerous areas including medical devices and food production
Assignment:
1) Delay time *be based on “method for this project”*
(a) Method [5 points]: How will you incubate your droplets to achieve the necessary incubation time (12 hours)? What factors are important to consider for your approach to work? Summarize your approach in a short paragraph (include citations). Either provide a sketch of your approach here or include this as a clearly labeled region of your overall device design sketch in question 2.
(b) Rationale [5 points]: What factors are important? What other approaches did you consider? Why did you choose this approach instead of the other approaches? (Include citations and/or reference class notes to support your case.)
I attached the file of the overall method including the system- droplet reservoir to be similar to the article “reservoir system for this project” and adding the water reservoir from “Starred paper” to the bottom.
2) Short answer questions (open notes/all resources)
Based on your understanding of the readings and Snapshot discussions: What is laminar flow? What is turbulence? How do we calculate Reynolds number, and how does this relate to laminar flow/turbulence? Use an example from “Life at low Reynolds number” by E. M. Purcell (I attached below) to support your writing. How do these concepts relate to your approach to solving the project?

For This or a Similar Paper Click Here To Order Now