Tianjin/FLIP-FLOP

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==<font size="4" color="#0000CC">Design</font>==
Flip-Flop, a huge family of basic electric elements, is widely applied to the field of electric circuit and construction of database. One of the most common members of this family is RS Flip-Flop, the key part of which is a clock-controlled element. Based on the conception of "Flip-flop" and synthetic biology, we designed the Genetically RS FLIP-FLOP whose output signal(Green Fluorescence) is regulated by additional input signal (the addition of IPTG). Besides this, we modulate the performance of Genetically RS FLIP-FLOP to optimize our original design.

<font size="3" color="#0099CC">'''1.'''</font><font size="3" color="#0099CC">'''Introduction to the logic rules of our flip-flop'''
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<td><center>[[Image:TJUzmlrules.jpg]]</center></td>
<td><center>[[Image:trigger.gif|150px]]</center></td>
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The logic principle of our design is shown above. Unless the input signal transfer from one stable condition to another (such as 0 to 1 or 1 to 0), the output signal would change into 1, otherwise it would maintain 0. Thus, the immediate response to emergency (input change) enables our design to detect signal variation in a short time, which is beneficial for process control because of its time-saving character.
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<font size="3" color="#0099CC">'''2.'''</font>[[Tianjin/FLIP-FLOP/Design1|<font size="3" color="#0099CC">'''Construction of Biological Circuit''' <More details></font>]]
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<td><center>[[Image:Flip-Flop.gif]]</center></td>
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==<font size="4" color="#0000CC">Modeling</font>==

Based on Ordinary Differential Equations, we construct the Mathematical Model of our flip-flop
system to test the result of our design and predict potential key factors deciding the results
of our experiment. According to the model, the variation of output signal responding to the input signal matches the typical
feature of flip-flop, there would no output signal only at the positive edge and negative edge of the input signal. The influence of 
AHL to the output signal is also considered. By changing the degradation speed of AHL, the fluorescence intensity
exhibit different behaviour which could be explained by principles of flip-flop. Finally, the parameter sensitivity is also tested to 
explore most significant parameter to output signals and it is discovered that the strength of promoter I, which controls the production of LuxI, the
promoter II, which controls the expression of LuxR, exert great effect on the final results. 

<font size="3" color="#0099CC">'''1.''' </font>[[Tianjin/FLIP-FLOP/model1|<font size="3" color="#0099CC">'''Construction of Mathematical Model'''</font>]]
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<font size="3" color="#0099CC">'''2.''' <font size="3" color="#0099CC">'''Model Result'''</font>
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<font size="3" color="#0000CC">2.1 <font>[[Tianjin/FLIP-FLOP/Model11|<font size="3" color="#0000CC">Model of the whole system</font>]]
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<font size="3" color="#0000CC">2.2 <font>[[Tianjin/FLIP-FLOP/Model2|<font size="3" color="#0000CC">Change the degradation speed of AHL</font>]]
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<font size="3" color="#0000CC">2.3 <font>[[Tianjin/FLIP-FLOP/Model3|<font size="3" color="#0000CC">parameter sensitivity</font>]]
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==<font size="4" color="#0000CC">Experiment</font>==

<font size="3" color="#0099CC">'''1.'''</font><font size="3" color="#0099CC">'''Ligation Strategy'''</font><[[Tianjin/FLIP-FLOP/More details|More details]]>
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<td><center>[[Image:TJUzmlligation.jpg|300px]] </td>
<td><div id="Experiment">
In order to assemble our device genetically in the shortest period, we try different method-Rolling Assembly and Parallel Assembly at the same time.
				<ul>
					<li>E.coli Cultivate</li>
					<li>Plasmid Extraction</li>
					<li>Verification</li>
					<li>Restriction enzyme digestion</li>
					<li>Agarose gel electrophoresis</li>
					<li>DNA ligation</li>
					<li>E.coli Transformation</li>
				        <li>Detection</li>
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			</div>  <!-- end of Experiment -->
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<font size="3" color="#0099CC">'''2.'''</font>
[[Tianjin/FLIP-FLOP/Parts Reservoir |<font size="3" color="#0099CC">'''Parts Reservoir'''</font>]]<br><br>
<font size="3" color="#0099CC">'''3.'''</font>[[Tianjin/FLIP-FLOP/Experiment/result|<font size="3" color="#0099CC">'''Experimental Result'''</font>]]
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<font size="2" color="#000000">Consider the significance of IPTG impulse as the input signal, we designed a series of experiment to search for most suitable condition to produce legible output signals, including the concentration of IPTG
([[high]] and [[low]] input signal), the time point for addition( exponential phase and stationary phase) and supplement of IPTG. The optimal plan is to add 0.5mM IPTG during the early exponential phase of E.coli cells, and the output signal together with other parameters have been summarized on the same graph which proves that every part of our device works as well as we expected. The slow degrading rate of Green Fluorescence Protein leaves our device some space to improve to achieve a more desirable result.</font><br><br>

[[Image:tjuexpff201.jpg|290px]]    [[Image:tjuexpff202.jpg|305px]]     [[Image:tjuexpff203.jpg|305px]]<br><br>[[Image:tjuexpff204.jpg|295px]]      [[Image:tjuexpff205.jpg|300px]]       [[Image:tjuexpff206.jpg|300px]]


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