NRG

The Bernhard group wants to use our membranes to separate pieces of DNA.  During their experiments they noticed that some of their samples caused discoloration over the summer.  Since then, I’ve been helping a new student to the project, Paul Black. He first started by testing pH, and found that higher pH leads to fast…

This is a repeat of the previous array experiment, but with a higher NaHCO3 concentration (1.85 mg/mL). Also, since these experiments require a lot of samples, I decided to cut chips off of wafer skeletons.  This one was w622.  As before, these were not RTP’ed and they were placed in the oven at 37C.  I…

Based on last week’s lab meeting, I made a “solution array” to test discoloration.  Specifically, I made 3 solutions of NaHCO3 (0, .23125, .4625, .925 mg/mL) and 3 solutions of NaCl (0.1, 0.5, 1 M).  I placed these non-RTP’ed w648 chips in the oven at 37C and took pictures at 4, 18, 72 and 120…

Last week, I looked at discoloration with different wafer numbers (639,670,672,683,685,702,703), pre- and post-rebuild.  This experiment was done in the oven at 37C, in PBS and without RTP.   Based on the starting color, w670 and w672 are the thinnest membranes.  These discolored rather quickly (1 day).  The only other membrane that discolored over 3…

I attempted a diffusion study with w685 three days ago. If you were following the comments on the w685 page, you’ll know I had some difficulty pipetting the protein solution into the well. I haven’t had this problem recently, and when I used to encounter this problem I would etch the remaining backside oxide with…

I guess there was a mistake in the last permeability plot.  The real data for the 4 bar plot should look like this: Unfortunately that doesn’t look so good anymore.  The third bar though is the one that I originally processed to have many more pores (w705).  The reprocessing gets it down in the 8%…

I’ve prepared a few slides of discoloration data for tomorrow.  The images didn’t copy over from the blog very well, but I think they are good enough for a discussion. labmeeting_oct211

More discoloration experiments.  No wafers were RTP’ed, and I looked at different wafer numbers.  For each experiment, I looked at discoloration in the oven at 37C and the incubator.  The labelling might be a bit confusing.  For the top right pictures, I looked at 4.4 mg/mL KHCO3 (left chip) and 0.35 mg/mL NaHCO3 (right chip)….

In my previous post, there still appears to be a discrepency between the calculated pore statistcis and the experimental permeabilities. I explored what I could do with the pore processing to bring the experimental closer to the calculated permeabilities. I set the minimum pore cutoff higher (15nm) and tried to remove any pores that did…