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…
We haven’t talked much about the optical properties of pnc-Si, but I thought it would be good to share some of the index and dispersion data I’ve collected using the ellipsometer. Below are plots of index of refraction (n) and extinction coefficient (k) vesus energy. The index is a measure of the optical density. The…
This is a follow-up post to “Protein Assay Test.” I realized that I never posted the final stag of my experiments, in which I finally got BSA to go through the membranes. In “Protein Assay Test,” I described several experiments that I set up to see if I could get BSA to pass through a…
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…
As I mentioned in the meeting this morning the SC267 samples have run out so I have begun testing SC269 for use in my experiments. This post pertains to a BSA diffusion experiment that I set up yesterday and allowed to run overnight. I took two SC269 samples; “treated” the first for 20min at 150C…
The following is a plot of rhodamine diffusion for the experimental system at various time point: In this figure, the rhodamine approaches equilibrium, as defined as a filtrate/retentate value of 1. The 9x well chips have a larger active area and quicker diffusion. I have performed simulations of this system using COMSOL, and in this…
Hi all, this is Henry. Leeanna Hyacinth, an undergraduate student from the McNair program, has recently completed a joint project between the Waugh, Palis, and McGrath Lab to create a bioreactor to amplify the number of mature red blood cells. Background: The Palis lab has discovered a method to amplify erythroid precursor cells (from 1…
I am having some problems with my electroosmosis device and I was hoping that people with more knowledge about the TEM chips might have some suggestions. For these trials, I used membranes from a wafer labeled 412-S. I am still using the PDMS device from my last post although now I have mini “clamps” that…
Due to the discrepancies between the 1D model and experimental runs with rhodamine, I have switched over to using COMSOL to solve for a 3D model. In this system, 200×200 um membrane squares with a 45 degree etch separate the two wells. The top well is set up with .5 mol/m3 of rhodamine, and the bottom…