The unwashed membrane has a definite “film” over it which makes the pores look textured. The MeOH & H2O seems to clear the pores up, but there are some places where there is remaining PVP that sticks to the inside walls of the pore.
Some transwell cell culture models require 1 week or more of cell growth in order to let the cells fully differentiate and form mature monolayer barriers. I had a couple of leftover samples a couple of weeks ago, so I measured the viability of cells on RTP’ed pnc-Si and PET transwells 7 days after plating…
The pump’s data sheet (located here) describes the pumps materials as: polyphenylene sulphone (PPSU) polyimide (PI) nitrile butadiene rubber (NBR) It also says that the acceptable particle tolerance is < 50 μm. This is the info we will need to determine the types of particles we can use with an in-line flow system.
The minimum essential medium elution assay with neutral red is a commonly used method for determining the cytotoxicity of a material, typically polymers1-4. The neutral red dye is only endocytosed by viable cells; relative viability can be determined by absorbance measurements from solutions of the extracted dye. After several weeks in the lab stabilizing the…
In the previous post it seems that the membrane pores do not significantly retard proteins and that the separation characteristics are due more to the slower diffusion coefficients of the proteins. However, in certain circumstances, the membrane may provide more of an effect. All of these experiments and simulations took place in a relatively large…
How to prepare the McGrath Lab Surface Contact Angle Goniometer (SCAG) from a disassembled form. I will create detailed posts on potential uses in the future. GENERAL NOTES Based on the McGrath Lab SCAG as it was on May 16th, 2013 Instrument layout: All bolts and set screws are 1/4-20’s. The angle screws are 10-32’s. Loosely =…
I set out to do an in depth study of adsorption to various surfaces using the sample buffer method. Midway through staining the multiple gels I noticed there was a problem. It looked as though glass and polystyrene adsorbed about the same amount of BSA as did pnc-Si. Details of the setup follow. Preparation: Using…
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The brightness of the image may even be significant. Was the beam noticeably dimmer with the thick PVP coating. IF so, the film is very thick.
Anyway, the pores are clearly covered, so the fact that water passes so easily must mean that the film either dissolves or is highly porous. It will be interesting to see if there is an effect on separations.