User:Michael S. Bible/Notebook/571/2014/10/01

Biomaterials Design Lab

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Analysis of Dialysis Begun Yesterday Post-dialysis solutions from all of the wells in the dialysis chamber were analyzed using UV-Vis using the following protocol: Remove 20 μL of solution from each chamber (10 in all) and run Bradford analysis Bradford reagent should be diluted 1:4 with water. Recall, 20 μL solution + 200 μL diluted Bradford + 780 μL Tris/NaCl buffer PS cuvettes, measuring 400 - 800 nm Don't forget to run a blank with just Bradford & buffer Don't forget to run your undialyzed Lysozyme stock Procedure taken from Dr. Fox Data Figure 1 shows the corrected UV-Vis Bradford Spectra for all Post-Dialysis Solutions. Figure 2 shows the corrected UV-Vis Bradford Spectra for the post-dialysis solutions from the non-protein side of the dialysis chamber. From the negative absorbance values, it is clear that there is no protein present. This is expected since the dialysis tubing used had a molecular weight cut-off of 3500 g/mol. Figure 3 shows the corrected UV-Vis Bradford Spectra for the post-dialysis solutions from the protein side of the dialysis chamber. It is clear from the spectra that there is still a lot of protein in each of the chambers, and the post-dialysis concentration of Lysozyme in solution almost perfectly matches the concentration of Lysozyme in the stock solution. Figure 4 shows the calculations done to determine the concentration of Lysozyme in each solution. From these calculations, it would seem that the actual concentration of stock Lysozyme solution is .28 g/L rather than .5 g/L as believed. This is because the stock solution is diluted by a factor of 50 when it is mixed with Bradford reagent and buffer.