20.109(F07): ECD experimental variations

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20.109(F07): Laboratory Fundamentals of Biological Engineering

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Since you are the first class to build electrochromic devices with bacteriophage, there are many variations to the protocols that may improve the biomaterials produced. This page should be used to document the experimental choices you've made along the way and their outcome. The collected wisdom that results will be used to make the experiment more robust for future researchers and may lead to alternative methods that could be explored. Thanks for doing experiments that haven't been done before and for letting everyone know how they work.

T/R lab

team name Iridium Chloride pH PFU/ul reacted with Iridium number of electrical pulses time, temp, shaking for growing nanowires comments on TEM data
TRpink 7.00 3x10^11 PFU/mL 35 2 hrs, room temp
TRyellow 7.00 1.21*10^5 PFU/ul, 1.21*10^8 PFU/ul 30/40, 30/30 2h, @RT Some crystals were found, but no nanowires
TRblue 7.00 6.12x10^7 PFU/ul 35 2 hours, room temperature saw some possible nanowire structures in the nanoscale, some large clumps too large to be nanowires, some clear structures (possibly salts?)
TRpurple 7.45 1.12x10^8 PFU/ul 25 pulses, mixed, then 5 pulses 2 hrs, room temp very small amount of nanowire structures. Most were too large to be formed around one phage. I also think I tore the copper grid with the tweezers which probably accounts for the lack of nanowires.
TRred 7.44 2.4E8 30 2hrs, rm temp
TRgreen 7.09 7.6E7 45 ~2hrs (1 hr: 55 mins), room temp spotted some nanowire structures, as well as clumps too big to function as nanowires. these clumps had a very crystalline structure and were not linear like the nanowires. we also spotted some structures thought to be simply uncoated phage.

W/F lab

team name Iridium Chloride pH PFU/ul reacted with Iridium number of electrical pulses time, temp, shaking for growing nanowires comments on TEM data
WFpink 6.94 1.53*10^7 (used 60ul instead of 40ul) 30 2hr, RT Not many nanowires were found. There was a relatively large amount of salt crystals dispersed throughout the grid, as well as some larger assemblies of crystal structures (these were not counted as nanowires because their sizes were not compatible with the dimensions of the phage).
WFyellow
WFblue 7.22 3.9*10^7 35 2hr, RT Lots of nanowire structures between 0.8 and 2 microns in length. Many nanowire shapes were irregular with lots of extensions and web-like interconnections, but individual "straight" wires were also seen. Also saw nanoparticles of iridium oxide as well as cylinders that were about the size of bacteria.
WFpurple 7.38 used WFblue's phage(3.9e7) 40/45 2hr, RT Part of the carbon slip tore, majority of slide did not have any IrO3. Along edges found evidence of iridium nanoparticles of fairly uniform size, as well as some nanowires. We also observed lines that may be unconjugated phage in parts of the slide.
WFred 7.00 2.8e6 (used 80ul instead of 40ul) 35 2hr, RT Many phage "nano" wire structures observed including ones up to 10 microns in length and 1 micron in width. Wires often were found together, forming a web of nanowire particles. Spots that indicate formation of iridium oxide crystalization without phage were also observed.
WFgreen 7.1 7.6e6 (used 53μL to increase ratio) 45/50 1hr 54min, room T Many phages were found that had dense coats of nanowires, often clumped together end to end. Some clumps, too large to be nanowire structures were seen along with rounded translucent structures that may be the result of drying water pulling salt ions together. Non-bonded IrO3 particles were also observed throughout the slides.