Difference between revisions of "Team:Arizona State/Notebook"

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<h2>Dissolving AHL in Ethyl Acetate</h2>
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<ul>
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<li>The first thing that must be done is to determine the molecular weight of the AHL, in this case the Lux AHL. </li>
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<li>Usually the synthetic AHLs are purchased from Sigma-Aldrich and depending on the volume of what is bought from the company, the milligrams it comes in is important when calculating how much must be dissolved. </li>
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<li>In the case of this project, the final stock concentration that was desired was 1*10^(-2)M. In this project, the highest AHL concentration desired was 1*10^(-4)M, but when plated the concentration is diluted down by 10^(-2). Therefore a starting concentrating of 1*10^(-2)M is beneficial. </li>
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<li>Then Stoichiometry must be performed to determine the volume in which the AHL in milligrams will be dissolved in, then how much ethyl acetate must be added to get to the desired final stock concentration. </li>
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</ul>
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<ol type="1">
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<li>First is to determine the molecular weight and container size the AHL comes in. </li>
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<ol type="a">
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<li>213.2 g/mol </li>
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<li>10 milligrams of AHL in the container</li>
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</ol>
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<li>Then is to determine the desired stock concentration.</li>
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<ol type="a">
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<li>This depends upon your range of concentrations, and how high the range is.</li>
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<li>Range is: 1*10^(-4)M- 1*10^(-14)M </li>
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<li>Therefore stock solution concentration: 1*10^(-2)M </li>
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</ol>
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<li>Then determine how large of a stock solution is needed</li>
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<ol type="a">
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<li>Since it is difficult to measure out exact milligrams of the AHL and back into a container without losing any grams, a large enough stock solution would be the most beneficial and use the entire AHL in the container.</li>
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<li>Desired Volume of Stock Solution: 500uL</li>
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</ol>
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<li>Determine Concentration of AHL contained in the stock volume</li>
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<ol type="a">
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<li>Here is where stoichiometry comes into play. The milligrams per stock volume must be converted into standard SI molarity. </li>
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<li>10mg/500μL * 1g/1*103mg * 1*106L/1μL * 1mol/213.2g = 0.094M </li>
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<li>The concentration found is the stock solution concentration needed for dilutions. </li>
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<li>Once done with the dilution to 1*10^-2 M, immediately put inside a -80C freezer for long term storage.</li>
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</ol>
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<li>With the concentration found above, it will be used in the C1V1=C2V2 equation. </li>
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<ol type="a">
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<li>C1 will be the concentration found above. </li>
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<li>V1 is the amount of AHL from stock solution into ethyl acetate solution</li>
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<li>C2 is the concentration of the stock solution </li>
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<li>V2 is the volume of the solution that is going to be further diluted and used in plating </li>
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<li>(0.094M)(V1)=(50uL)(1e-2M)</li>
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<li>V1=5.32uL AHL</li>
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</ol>
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<li>Subtract AHL volume from total volume</li>
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<ol type="a">
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<li>This volume of AHL will be used to find the volume of ethyl acetate to dilute the AHL into a 1*10^-2M solution. </li>
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<li>So, 500 – 5.32uL = 44.68uL of ethyl acetate</li>
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</ol>
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<li>Add these two amounts together in a 1.5mL centrifuge tube </li>
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<ol type="a">
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<li>Mixing the Tube:</li>
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</ol>
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<ol type="i">
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<li>Pipette up/down</li>
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<li>Vortex</li>
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<li>Spin down (using tabletop centrifuge) </li>
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</ol>
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<li>Immediately place dilution in the -20C freezer for immediate use of plating or for further dilutions.</li>
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</ol>
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Revision as of 21:28, 23 October 2017