In preparation for Tuesdays meeting Jim asked me to prepare this chart to compare the results of the treated and untreated diffusion experiments from this summer. The chart values given are the percent concentration of the sample filtrate in comparison to the original “feed” solution. For instance in all of my experiments the initial “feed”…
I made a post yesterday showing that in 20mM HEPES, pH7.5, +10mM NaCl solution equivalent amounts of DDM were diffusing through the “treated” and “untreated” SC256 samples. Additionally it appeared that minimal amounts of BSA were diffusing across either sample. I set up another diffusion experiment and let it sit overnight. DDM analysis: As observed…
Yesterday I posted the results from an experiment testing diffusion of BSA and DDM with salts (10mM) across “treated” and “untreated” SC256 samples. The results posted yesterday showed relatively equal amounts of DDM diffusion in both the “treated” and “untreated” case. For the BSA diffusion however the results showed that a greater amount of BSA…
In my last post I showed that using buffered solutions instead of Di-water we could obtained similar results with SC256 as we had with SC269. I used 20mM HEPES at pH7.5 with no salts and showed DDM diffusion through both “treated” and “untreated” SC256 samples. Additionally I showed that “treated” SC256 samples appeared to slow…
On Friday I posted results from a diffusion experiment in which I tested “treated” and “untreated” SC256 samples against the diffusion of a mixture of DDM and BSA. The DDM-BSA solution contained an initial DDM concentration of 1.0% and an initial BSA concentration of 2.5mg/mL; the solution also contained 20mM HEPES and was at a…
In an effort to conserve membrane samples I am working to run diffusion experiments with a mixture of BSA and DDM. This will only use 2 chips instead of 4. In our meeting on Tuesday it was mentioned that BSA can be detected using the TECAN at 280nm, while DDM is not detected at that…
After our meeting with Professor Dumont on Tuesday it was decided that we needed to try and perform the BSA/DDM seperation with a more porous membrane (to allow for eventual pressurization). SC256 was choosen and as an initial step I ran a simple small dye diffusion experiment to verify that the pores were open. As…
The last post I made about the BSA/DDM separations using “treated” and “untreated” SC269 samples explained a problem I was having in which the initial retentate drop was diffusing around the edge of the sample chip. It seems that SC269 is naturally more hydrophillic than SC267 therefore when “treated” it becomes so hydrophillic that the…
Yesterday I posted results of a diffusion experiment using rhodamine and fluoroscein that showed the pores in SC269 are open both before and after treatment in the UV-Ozone system. I set up another diffusion experiment to test “treated” and “untreated” SC269 samples with diffusion of BSA and DDM. As a reminder the focus of my…
Yesterday I posted my results from a BSA diffusion experiment using “treated” and “untreated” SC269 samples. To ensure that the pores in SC269 are indeed open I took a step backwards and set up a diffusion experiment using small dye molecues; rhodamine and fluoroscein. Using Jess’ diffusion cell I set up a matrix to test…