Metallized Membranes

Separations were performed at 2 different salt concentrations with equal volume filtrate and retentate (to avoid dilution problem). Separation time was 40hrs rather than the usual 24. The lower salt concentration run has a lower cutoff – which is just like what we see in the DNA separations. Remember though that proteins have different charges…

Bernhard Group: Discoloration was observed during DNA separation experiments.  Further study led to these results: No discoloration observed with low pH buffered NaCl. Discoloration with high pH buffered NaCl. Worried that Cl was the culprit, sodium acetate was tested.  Discoloration observed with sodium acetate. In one early experiment, 4 areas were tested on one chip. …

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…

This paper (SiN paper) by Ulrich Rant et. Al. details several experiments conducted with a single pore drilled through a SiN membrane via TEM. They measure the relationship of pH vs. zetapotential for both a model protein (avidin) and their membrane, and then see how protein moves across the membrane at different pH’s. Translocation is…

As the title states, I partially etched some different material (Wafer 2238, 100 nm NPN) to create nanofeatures with blown out holes. With a thicker membrane, we can blow out the pores more (etch longer) without compromising the strength of the material (with regard to templating purposes). These membranes were fractured and coated with 6…