This past week I ran multiple experiments using the pressure cell and sep-cons. I used membranes from W684 for the sep-cons since the burst pressure of these memebranes is high (around 3.65-10Psi). I added 100uL BSA to the Sep-Con and put 20uL 1xPBS on the backside. Before adding the NC to the sep-con, I assembled…
Creating an array to hold a pnc-Si wafer to proving to be difficult. The PDMS spreads too rapidly though the NC to form a consistent array for the pnc-Si membrane (and eventually wafer) to rest on. I’m still running different trials of the PDMS on NC to see if I can get the array to…
What has been accomplished thus far: Able to detect BSA on NC membrane with the use of Ponceau S stain With PDMS array on NC, no BSA leaks through the area covered by PDMS Initial trial done with 10:1 ratio of elastomer base: curing agent. Later 3:1 and 5:1 ratios done. 3:1 is too sticky…
During the past week I tried various methods of applying PDMS to nitrocellulose. Below is a table of what the PDMS array looks like on the NC before curing in the over, and after applying 1mg/mL BSA and staining with Ponceau S. When I painted the PDMS on, I used the thin side of the…
I finished the first experiment to look at rhodamine transport across commercial transwell membranes. I was mainly interested if there would be enough transport into the basolateral chamber to measure the rhodamine with the spec. Experimental details: both chambers in PBS and at room temperature, spinning on the rotomix, 0.5mM initial rhodamine in donor; sample…
As mentioned previously intact membranes show a flux comparable to membranes with pinholes during desalting experiments. To confirm this a third intact membrane test and two pinholed tests were run under the exact same conditions. Previous pinholed samples had different NaCl solution volume in the SepCon, I wanted to remove any variability caused by this….
Jess showed me how to use the diffusion chamber to separate proteins on the membranes. I ran a gel to see if any proteins appeared in the filtrate. The gel is posted below: The lanes are (from left): protein standard, control, retentate 1, filtrate 1, retentate 2, filtrate 2. It appears that protein diffused through…
I was having trouble using the spectrometer to measure rhodamine concentration in the stir cell. I ran a standardized absorbency of the serial dilution of rhodamine. The curve is posted below. It appears to be linear. The molarity of rhodamine must be above 2uM in order for the spectrometer to read it. I think I…
Lingyun and I used the stir cell and spectrometer to measure the diffusion of rhodamine across the membrane. This was the first time I was able to construct an experiment in the stir cell while keeping both membranes intact. In the past one membrane would rupture or the cell would leak too much. For this…
Mike and I tried to pass 3 um beads mixed with rhodamine through the stir cell to prove that, if the membrane we intact, only the rhodamine would pass through and not the beads. As seen in the pictures below, only the rhodamine passed through, not the nanoparticles, since these particles are 100x larger than…