In order to support the idea that RTP treatment does not change membrane pore characteristics (as shown by Anant in the rhodamine diffusion study) I processed TEM samples that were not treated, RTPed in Ar, for 5 minutes at 800C, and RTPed in O2 at 800C for 5 minutes (I believe this was not a…
Dave delivered W637, a wafer made using the sample recipe as W504, to us today. This wafer has a high occurrence of single pinholes, with only 12 samples pinhole-free. I also noticed some odd features on the membranes, shown below. In the reflection images above, some sort of substance is on the membrane. In the…
Last week I tried to diffuse Cytochrome C through our membranes onto PVDF and PES membranes to see if we can detect protein adsorption on the other membranes. The trial illustrated that cytochrome c will diffuse through our membranes and stick to the PVDF and PES membranes. I ran the experiment again, but I used…
The 20nm deposited polymer film permeability is approximately 1e6 barrers, while bulk polyimide permeability is less then 100. So the experimental value is too high. There are two possibilities to explain it: First, the pores are partially open and 20 nm thick layer is too thin to cover big pores. I will try AFM this…
I’ve been working with the Corning transwell inserts and our SepCon units a bit recently. The addition of the Dremel last week has allowed better control while cutting the transwells, even without the right angle attachment (which will allow cutting in the “drill press” mode). I attached a picture of the process and final unit….
Bill Bernhard’s group approached us about using pnc-Si membranes to separate DNA species by diffusion. Bill’s lab studies the effects of ionizing radiation (ex. X-rays, gamma rays, UV light) on DNA using electron paramagnetic resonance (EPR). There are three major species of DNA that they wish to study using our membranes: short oligonucleotides, larger supercoiled…
Due to our desire to improve membrane stability in cell culture, different methods of treatment have been mentioned to try, including carbonization and silanization. W606 was treated with UV/ozone at 150C for 20 minutes, followed by silanization performed by some of Chris’ colleagues. I then ran a basic discoloration test in DMEM +10% FBS (the…
Previously W514 was tested with different RTP conditions (varying time at 800C, all in Ar); the results were difficult to interpret as the cells were confluent (in some cases it was hard to see membrane breakage). We therefore decided to run a similar test again, with a slight change in O2 addition during RTP. O2…
Following time lapse movies show the spreading of HUVECs on pncSi and glass ( @ 37C, in L15 media supplemented with 10% FBS) over a time period of ~4 hrs. HUVEC spreading on pncSi HUVEC spreading on glass
This was something I set up a few days ago and finally got a chance to run the gel. I was curious to try this after the previous forced separations using brain extract. If you recall, the “separation” using the pressure cell did not have a visible cutoff and all of the bands appeared in…