Objectives
 Calculate the amount of AgNO_{3} to add to LB media solutions for desired final [Ag^{+}].
 Remove PLA films, made on 2013/02/19, from glass molds.
 Soak PLA films in pure H_{2}O to test for Ag^{+} leaching with a silver ion selective electrode.
 Run Xray on 100AgLMT.
 Harvest DH5αT1 cells for Ag^{+} cell growth inhibition studies.
DH5αT1 Cell Harvesting
 Five cell starter cultures, made on 2013/02/19 were obtained and their absorbance at 600 nm was recorded.
 Please refer to Keyun Wang's entry for the absorbance data and the protocol to pellet the cells.
XRay Diffraction on 100AgLMT
Calculations
 Two sample calculations are given as examples. The final [Ag^{+}] in 50mL solutions of LB media was calculated as follows:
1 μM Ag^{+} in 50 mL of LB media
(0.0105 M Ag^{+}) × V_{1} = (1×10^{6} M) × (50 mL)
V_{1} = 0.00476 mL of 0.0105 M AgNO_{3}
10 μM Ag^{+} in 50 mL of LB media
(0.1 M Ag^{+}) × V_{1} = (10×10^{6} M) × (50 mL)
V_{1} = 0.005 mL of 0.1 M AgNO_{3}
 AgNO_{3} solutions made on 2013/02/05 and 2013/02/13 will be added to the LB media solutions in the following amounts:
Final [Ag^{+}]
 Volume of AgNO_{3} Solution Added

1 μM  4.76 μL of 0.0105 M

10 μM  5.00 μL of 0.1 M

100 μM  50.0 μL of 0.1 M

1 mM  500 μL of 0.1 M

10 mM  5000 μL of 0.1 M

 Note that for each volume of AgNO_{3} added to the LB media, the same volume of LB media will first be removed from the flask to maintain the final concentration of Ag^{+}.
ISE Study of PLA2002D + 5 wt% 100AgLMT
 Calculations
 To determine maximum [Ag^{+}] possible, assume that all Ag^{+} leaches out of solution.
 The solution contained 50 mL pure H_{2}O and 1 mL ionic strength adjuster. The recommended ratio of solution to ionic strength adjuster is 50 mL to 1 mL. Then, 0.50 g of film was added to the solution.
(4.47 × 10^{8} mol Ag^{+}) ÷ 0.051 L = 8.76 × 10^{7} M or 0.876 μM
 Protocol
 Pour 50 mL pure H_{2}O into a clean, dry 250mL Erlenmeyer flask and add 1 mL of 5 M KNO_{3}.
 Measure the conductivity of the solution with the ISE.
 Place a single 0.5 g piece of film into the flask, swirl, and measure the conductivity.
 Wait 30 min, then measure the conductivity again.
 Repeat the above step 5 more times.
Time [min]
 Conductivity [mV]
 [Ag+] [M]
 mol Ag+ [μmol]

0  384.9  0.000204407  10.42474353

30  379.9  0.000163526  8.339821664

60  372.5  0.000117534  5.994210823

90  367.2  9.27767E05  4.731609351

120  366.8  9.11352E05  4.647893756

