In my last post, I concluded that switching the o-ring position from below the membrane to the top in the sepcon produced no leaks. The reason for this switch was to reduce the 1mm “dead-space” (created by the o-ring) that…

PES Membranes: I tested 100 and 300kD PES membranes from Pall. 5 and 20 nm particles were used in both water and 10mM KCl. I won’t show all of the data, but I didn’t see any particles in any of…

In these trials, I used TER to look at the resistance between membranes with different amounts of pinholes. Finding a trend would produce a quicker way to scan for pinholes as opposed to checking each slot on the wafer with…

The new electroosmosis wafers have randomly distributed chips with 1, 3, 6, or 9 .1x.1mm freestanding pnc-Si squares.  The idea is that we can use these to get a better EO rate vs. active area curve.  SC125 seemed to have…

In my last post on HUVEC intercellular junctions, I just showed cadherin staining.  I repeated this protocol but also tried immunofluorescence for ZO-1, the tight junction protein. These are HUVEC P7, 6 days post-seeding @ 50,000 cells/cm2.  I looked at…

The BT method mentioned in this post seemed to give stable particles, but the BSA-Au did not work in separations.  After about 24 hours, the particles retained pink color but seemed to settle in tubes.  This may be due to…

One of the markers of endothelial monolayer maturation/barrier function is the expression of adherens junction and tight junction proteins.  The adherens junction is composed of transmembrane proteins called cadherins (among other proteins) that link cadherins of neighboring cells to the…

I had some old HUVEC (P8) on pnc-Si transwells and PET Costar transwells that I didn’t know what to do with.  So I tried a permeability study to see if there were any unexpected roadblocks in the protocol. I seeded…

In my previous transport post here, I showed O-ring placement data which was motivated by my thinking about the unstirred water layer (UWL).  I think it’s helpful to think about the total resistance to transport through transwell membranes as a…

After diffusing through a polymeric or pnc-Si membrane in the transwell format, diffusing molecules meet an “unstirrred water layer = UWL” on the bottom of the membrane.  The UWL acts as another resistance to transport into the receiver compartment.  According…