During the last production run, we experimented with varying the RTP annealing time (1 min vs. 5 min) at three different RTP temperatures (1050 C, 1100 C, 1150 C) in a 30 nm thick membrane.  Below are the TEM micrographs with corresponding histograms and average pore diameter/porosity plot. Of note is the 1050 C anneal…

The human IgG did not seem to diffuse through the membrane the first time we conducted a diffusion experiment. Barrett believed that the lack of diffusion was most likely due to protein aggregates blocking the pores. So, the human IgG was filtered, and this post is the result of a second round of diffusion experiments….

During the history of pnc-Si fabrication, we have always observed that pore formation is intimately related to the crystallization process.  In general, large nanocrystals in a film correspond with larger pore diameters.  A partially crystallized film will have a low density of films.  Following the work that describes crystallization of a-Si in terms of kinetic…

In my last couple of posts with respect to endothelial cell culture on pnc-Si transwells, I presented images of cell clumps over the active pnc-Si membrane area of transwells (here and here).  There were dead cells associated with these clumps and this is a concern for barrier function experiments.  This post shows a counter-example of…

I’ve repeatedly seen cytotoxic edge effects when I grow bEnd3 cells on the bottom of PET membrane transwells.  Here’s a post of images.  I’m getting closer to co-cultures of bEnd3 and NG108-15 cells on opposite sides of membranes and I’ve been investigating the optimal arrangement of the different cell types (bend3 on top or bottom?). …

Last week the rotation stage broke in the middle of a deposition.  The wafer came out looking very non-uniform, and judging by the color of the film there was at least a 10 nm gradient.  Since I’m not sure when the motor stopped, it’s hard to say if the underlying oxide is non-uniform as well,…

Last week, a RTP temperature series was performed on 15 nm Si membranes with 20 nm and 40 nm oxide layers.  The purpose of this study was to 1. evaluate the effect of a thicker oxide on pinhole density and 2. identify a dependence of morphology on oxide thickness.  Below are two graphs summarizing the…

There has been some confusion lately with what we should name the compartments in diffusion.  Here’s what I’ve come up with: Top/Compartment with initial sample: Retentate Bottom/Compartment to which things diffuse: Dialysate The original word we were using for dialysate, filtrate, implies an active process and was criticized by scientists at NAMS.  While dialysate implies…

SepCon Experiment (Carrie): Does it work in a SepCon format? Use “Protein A Beads and IgG Binding and Filtering (with SepCon Format)” 9/29/09 Make Buffer B at pH 3 9/30/09 1) Rinse off ethanol 2) Add IgG Take absorbance reading of 1 aliquot of IgG (2×10μl samples) [D7= 0.565abs, D8=0.63abs] Transfer beads to 2ml centrifuge…

Test of Binding/ Unbinding (Carrie and Barrett): Test to see if we can successfully bind Human IgG to the protein A beads and then remove it with buffer B. After ordering the new human IgG and protein A beads, I have been working on a higher-quality analysis of the binding and dissociating of the IgG…