Objective
To create more AUNP with lysozyme fibers as most of those from 9/15/15 failed to make fibers. Only one 5mL and four 1mL samples generated fibers. The other goal was to make 500 mL of 10 mM Tris buffer, pH 9 and 500 mL of 10 mM phosphate buffer, pH 7.
Description
The instructions for the day can be found here.
- Making the AUNP with lysozyme fibers
- We followed the same guidelines as we used for 9/15
- There were only enough reagents to make 4 1mL samples
- Making the buffers
- Tris buffer: 500 mL, pH 9, 10 mM
- Used buffer calculator to find the mass of Tris buffer required
- Selected Tris for molecular weight, entered 500mL for volume, and 0.010 for molarity. Calculator advised adding 0.6157 g of Tris.
- Phosphate buffer: 500 mL, pH 7, 10mM
- Used phosphate calculator to find amount of dibasic Na2HPO4 and monobasic NaH2PO4 required
- Entered 7 for pH, 10 mM for buffer strength, ___ for MW_Na2HPO4, and __ for MW_NaH2PO4. Calculator advised adding 0.39816g of monobasic sodium phosphate and 0.36831g dibasic sodium phosphate
Results
- AUNP with lysozyme fibers
- No fibers were created, all solutions turned purple but no fiber formation
- Buffers
- Tris buffer: 500 mL, pH 9, 10 mM
- Added 0.608g of Tris to distilled water in a 500mL volumetric flask
- Mixed for several minutes with a stirbar
- Added 1M HCl to obtain a final pH of 9.036
- Final conductivity was 172.6 mS
- Phosphate buffer: 500 mL, pH 7, 10mM
- Added 0.399 monobasic sodium phosphate and 0.369 g dibasic sodium phosphate to distilled water in a 500mL volumetric flask
- Added NaOH to reach final pH of 7.058
- Final conductivity was 1316 μS.
Matt Hartings How did you make your buffers? What were the final measurements (conductivity and pH) that you took? Did you have to add HCl/NaOH to either both? What were the calculations/measurements that you used for the phosphate.
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