Stir Cell
This is a side view schematic of the experiments I’m setting up in Mike and Derek’s stir cell. The membrane separates two wells. In the well where the membrane is flush with the wafer I add 300uL 5nm gold in H2O. On the other side I add my buffer and a stir bar. Adding a stir bar on both sides would occasionally break the membrane since the stir bars have some affinity for each other and they will rub on the membrane.
In my latest experiment, no 5nm gold passed through w334 visibly or by analyzing with the Zetasizer after stirring for 3 days. This must be an effect of the electrostatics. My next trial will be to test 20nm polystyrene in this system, which seems to be stable in PBS.
In other news I tried separating depleted plasma using w334, but everything passes through again. According to Dave’s post this wafer has fewer tears because it was RTP only, but either the pore sizes are too large for separation or there are enough tears on the surface to allow uncontrolled diffusion. Also that same middle band appears in the filtrate more than the retentate (gel scan forthcoming).
Jess, I am ignorant to the subject, but are there any magnetic forces at the nano-scale? If so would gold be affected, and could we use the potential to our advantage – to help flow across the membrane??