W509X, with single 100um by 1000um slits, was tested for air permeability and burst pressure. Prior to testing, I inspected all membranes for pinholes.; every sample had pinholes on the membrane perimeter, as shown below. The first two images are in reflection mode (pinholes appear black) and the last is a transmission image (pinholes appear…
I tested four samples (-1,1); (-1,2); (-1,3); and (-2,4) for air permeability and burst pressure. The first three samples showed no measurable air permeability for three attempts each. The sample from position (-2,4) did have a very small air permeability of 11.2 cc/(cm2*atm). Based on the results of rhodamine diffusion it seems odd that I…
One area of use to explore for the membranes is desalting, the removal of salts from solutions (such as those containing proteins). Two dialysis products made my Thermo/Pierce were tested to develop a protocol and test manufacturer’s claims. These products are the mini-dialysis unit on the left and the dialysis cassette on the right; both…
HUVEC adhesion was tested on different substrates. This time solid chips w/o membrane slits were used and expected results were obtained. I think from all the adhesion studies done, it could be concluded that initial adhesion on pncSi is as good as any other favorable substrate. Hence, the initial low density on pncSi was due…
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…
Fibroblast adhesion experiment was done using poly-lysine coated plastic and teflon coverslips as positive and negative controls repectively. Poly-lysine is a polypeptide that gives the cells a sticky surface to adhere to. Teflon coverslips are used as negative control because they do not promote cell adhesion. Difference in morphology of cells could also be seen…
Four more adhesion experiments were carried out and the results can be seen in the following charts. Based on the average of the four trials it can be elucidated that the initial adhesion (after ~7 hours) is pretty much the same in all the substrates. In trial 3 & 4 it can be seen that…
Two more adhesion tests were run recently, one on Tuesday and one on Wednesday. For both tests cells were imaged after five hours. Fibroblast trial 3 was the first test where the optimal cell density (assuming 100% of cells are detached by trypsin and 100% attach to the substrate) was measured using a hemacytometer. Of…
We have been wondering about the reason for discoloration for a while. This could be due to the pH of the solution or the concentration of the salts in the solution. To narrow down our vision on this, first we tried using solutions with different pH values ranging from 4 to 9 in room temperature….
Thus far three HUVEC and two L13T3 growth tests have been conducted on substrates including glass,pnc-Si, tissue culture plastic, and untreated plastic. Only one test with untreated plastic has been run for each cell type. Cells on Si samples are not on the slits but rather on substrate surrounding. It seems that HUVEC proliferate more…