EDIT: This problem was solved thanks to Tejas. It turns out that Falcon BD transparent 96 well plates absorb in the UV range, and are best used for bradford assays or anything that measures absorbance higher than the UV range. Apparently they sell UV-inactive 96 well plates, but they are very expensive. Josh Winans and…
Karl, Charles and I measured the burst pressure and permeance of some 30-50-30 and 30-100-30 NSN. Burst Pressure: The SEPCONs readily burst at pressures under 1 psi when the flow was directed from the backside of the chip through the membrane. The membranes were able to withstand higher pressures when the pressure was applied from…
Still trying to reproduce Joe’s large pore material on SEPCONs using NSN stacks. This post has data from two wafers with 30/50/30 and 30/100/30 NSN. RTP is 1000C 50C/s for 1min. Nitride is etched off by placing samples in 50% HF for 3.5 minutes. (~30s after that the films start to lift off) I start…
We are trying to reproduce the very small pores Joe created with 30/100/30 OSO and large pores created with 30/100/30 NSN using a SEPCON pattern. (Joe’s previous post.) We had a problem with several chips releasing from the center of the wafer prior to completely clearing all the features. In the future we will use…
With Joe’s help, I was able to take some SEM images of the samples that I performed my previous set of separation experiments on. Sample 1: The obvious aggregation in this sample (exemplified by the ‘victory eagle’ blot in the second image) is observed in all five of the samples. What we can’t know is…
In early May, the Barcikowski lab shipped us four samples of gold nanoparticles for us to run separations on. They took forever to get here, and had aggregated and precipitated by the time they arrived. About a week ago, the lab sent another batch of four samples (which differed slightly from the samples they sent…
What we’d like to have accompany the Sepcon filters is a general way to tune the pore sizes for any given separation. If, for instance, someone wanted to have a filter cutoff of 12nm, we could create a custom wafer with a mean pore size of roughly 17nm. But it would be much easier (and…
Given the mixed results of discoloration of RTPed samples from W613, which include no discoloration until 7 days (when the experiment was started within 2 hours of RTPing), and discoloration within 2 days (experiment started 8 days after RTP) I ran another discoloration test. This time I started the experiment within an hour of RTP,…
The ultimate experimental goal of the desalting project is the removal of salts from a salt/protein solution while fractionating certain sized proteins with maximum protein retention and recovery.Thus far we have characterized the flux of salt through our membranes which show flux an order of magnitude greater than cellulose membranes. Our next step is to…
Given the low burst pressures of recently produced wafers Chris requested I burst pressure test some samples in two different orientations: well side facing away from the positive pressure source and well side facing towards the pressure source. The standard protocol I follow is to test the samples with the well side facing the pressure…