Similar Posts
Update: automation analysis of cell migration and fibronectin fibril characteristics
ByHenryHi all, Recently we finished drafting the manuscript titled “Porous substrates promote early endothelial migration at the expense of fibronectin fibrillogenesis.” This manuscript will feature the cover illustrated by Brad (our new medical illustrator in the Gaborski Lab): Long story short (another illustration by Brad): Left (nonporous control substrate): cell traveled slower, covered smaller…
HUVEC Adhesion with Controls
HUVEC adhesion was measured on glass, tissue culture plastic, and pnc-Si, with poly-lysine coated plastic and teflon coverslips as positive and negative controls. Adhesion on pnc-Si was low, this could be due to cells being lost through broken slits or possibly some other unknown factor. Adhesion tests are continuing, with the use of solid Si…
Metal deposition at different positions
I am trying to deposit metal on the membrane with minimal deposition inside the pores. The image below is an example of how the film quality and thickness change when the sample is positioned at different angles and distances from the source in the same deposition run. The schematic in the corner of each SEM…
KMnO4 as a Platform: absorbance vs. concentration
ByJimI discussed with Jess the possibility of using a negatively charged dye. People did use such dyes before but we probably need to order them at this time. Since now we can use the spectrophotometer to determine the concentration of a solution, we might be able to make use of the potassium permanganate (KMnO4) solution…
Movable Cutoffs in Diffusion
Follow-up to Pressurized Movable Cutoffs. Wafers 670 and 673 were not holding up in PBS for the 24 hour diffusion experiment duration. RTP treatment at 800C for 60s enabled chips from both of these wafers to last 24 hours. Here are the results from the gels: We definitely have two different cutoffs in these experiments. …
Filtration of DNA and Bugs @ INT
ByJimTwo experiments were performed to explore application of SiMPore filters within INT’s microfluidic cartridges to allow the capability for pathogen type specificity in nucleic acid purification. 1) The first experiment tested the efficiency at which nucleic acids could pass through the membranes. T4 polynucleotide kinase was used to 32-P radiolabel two different sized PCR products:…
5 Comments
Comments are closed.

Terrific looking study. Now we just need a little help interpreting … what could Ar/RTP without UV/ozone have done to change things?
Jim,
Even without UV/ozone treatment before RTP, there is an initial native oxide on silicon. RTP is basically annealing. RTP is normally used to either diffuse dopants, cure lattice distortion or site dislocation due to implantation, and densify the oxide layer. Here denser oxide should play the role improving chemical stability.
The thing I am not 100% sure is, since native oxide is about 1-2nm thick, is that already enough for isolation?
Anyway, something about UV/ozone…
when I set up the UV/ozone, I thought it was only used to do the contamination cleaning… actually I don’t think incubate silicon in ozone chamber can result in a thick oxide layer.
Some of the membranes break over time even though the color is holding steady. I assume that to take these pictures you need to remove the membranes from the liquid and partial drying might be causing this?
Also some membrane were broken from the start. We should discuss (or test) the ability of the membranes to hold up to these treatments.
It seems clear that the RTP treatment is helping with bio-stability of the membranes, so we should now start looking into weather we are creating any other problems with flow and/or strength.
The whole reason for trying the RTP treatment was to see weather we can further stabilize the surface oxide and/or grain boundaries. We apparently are, and it’s curious that everything that was tried with the RTP worked over this experimental duration. Are these studies ongoing? What is our target stability – say 1 week?
In these experiments I’m not too concerned about the membranes breaking after drying. If they were broken before drying, I would be slightly more concerned. This is really problematic material anyway, so we cannot draw any real conclusions about the material strength.
Update after one week duration: We were wondering why should Ar RTP help! Here’s something that’s showing up.. The Ar RTP samples started discoloring in a week’s time, whereas the O2 RTP treated samples still remain intact in DMEM. Thus, RTP is helping for sure but O2 RTP is better than Ar RTP.