Last week’s production yielded two wafers (502 & 504) with defect-free membranes. 506 had a high pinhole density. These wafers have a TEOS mask and were annealed twice; the first anneals did not produce pores so they were annealed again at 1000 C. From these results, it seems that the first anneal “seeds” pore formation…
I set out to do an in depth study of adsorption to various surfaces using the sample buffer method. Midway through staining the multiple gels I noticed there was a problem. It looked as though glass and polystyrene adsorbed about the same amount of BSA as did pnc-Si. Details of the setup follow. Preparation: Using…
I recently tested the burst pressures of samples from W510, 511, and 513. None of the membranes are pinhole free. Silicon thickness varies (15 nm, 10 nm, 20 nm). See Dave’s post for complete fabrication information. W513 has noticeably higher burst pressures compared to W510 and 511. Overall W510 is in the worse shape overall,…
In the previous adsorption trials I compared SepCons to MicroCons and NanoSeps. The SepCons appeared to have higher adsorption, which we thought may have been a result of the plastic used in the SepCon. I then removed membranes from MicroCons and NanoSeps and compared to pnc-Si membranes in the same manner as outlined in the…
This is the protocol I use to measure band intensities. At the end of the explanation I will post and review my recent results concerning silver stain densitometry. First load a digitized gel into ImageJ Select Image>Type>8 bit to make it black and white. Select Invert to make the bands have positive intensities. Go to…
I recently attempted a fibroblast (L1 3T3 cell line) growth test. The cells were seeded at too high of a density, so growth curves can’t be produced. However I checked cell viability and pnc-Si discoloration. As expected RTP treated samples discolored later than treated samples. Samples with cells seemed to discolor sooner than samples without…
The following changes were made in this adsorption study: The MicroCons/NanoSeps were not spun. We will just characterize the differences between the materials. The pnc-Si membranes were assembled into SepCons because of the potential adsorption to the plastic surfaces. Mass standards were run on the gel in order to allow the measurement of protein concentration….
To improve our knowledge of pinhole formation I have started counting pinholes on W510, W512, and W513. I also am playing close attention to areas surrounding the samples that have been completely etched, to see if this correlates to pinhole number. A schematic of W510 with number of pinholes is shown below. I would like…
Last week I etched three wafers of different silicon thicknesses (10 nm, 15 nm, 20 nm). All the wafers had a TEOS mask with the standard three layer sputtered film on the front. Not that surprising is the fact that the thinnest membrane showed pores while the 15 and 20 nm membranes did not at…
Previously I have shown that sample buffer can be used to lift adsorbed proteins off polymer membranes, which can then be imaged on a gel. I have used a similar procedure to assay adsorption on pnc-Si membranes. I used 4 samples from wafer 216 that all had pinholes. I incubated a drop of 1mg/mL BSA…