I found some good descriptions of hemodialysis experiments using rats. They all use a method possibly first described by (Rockel et al., 1978). (Galons, Trouard, Gmitro, & Lien, 1996) at U of Arizona used nephrectomized male Spraque-Dawley rats (Holtzmann Co.,…
Tag: dialysis
Urea/f-BSA/cytochrome c concentrations in retentate after dialysis: 12 hours
Continuing on the path of hemodialysis, we are increasing the complexity of the fluid being dialyzed. In this long-term experiment I will pump 100% serum with added urea (1mM) cytochrome c (1 mg/mL) and fluorescent BSA (1 mg/mL). So I…
Long Term Urea: Evaporation measurement and Pressure Calculations.
The initial measurements with multiple tests tubes containing either Serum or PBS failed to demonstrate evaporation and in fact the weights of the collection tubes increased after sitting in the refrigerator overnight. Perhaps the tape collected water? At any rate…
Long Term Urea Clearance in 100% Serum
I ran a 30 hour urea clearance with 100% serum through the single slot dialysis device. The now standard protocol was run. The single slot chip was annealed in the RTP for robustness then clamped into the acrylic/PDMS flow fixture.…
Long Term Urea Clearance in Serum
I made 50 mL of 30% fetal bovine serum (FBS), 70% PBS, 0.5 mM urea. Pumped with syringe pump at 5.6 µL/min through an untreated and EA treated single slot dialysis chips in a stirred beaker of PBS (two separate…
Counter Flow Dialysis Device Design
Upper and lower gaskets used to make a counter flow device. The danger is that the enclosing pdms can easily flex into the membranes on the flat side of the chip. A hard plastic cover can be used to prevent…
Multiple Chips packaging Concept
While my focus will be on packaging a single multi-channel chip device, I have captured here an initial concept for packaging multiple channels. The technique required is the application of verticle PDMS structures to direct blood and dialysate to and…
The effect of pump rate and channel height on Urea clearance (COMSOL modeling)
Comsol modeling was done to find the ideal channel height and volumetric flow rate. What is clear from the simulation is that ever increasing flow rates in the model lead to increased clearance and decreasing channel heights give some benefit…
Long Term Urea Clearance (8 hours)
SET-UP Syringe pump: 5 mL of 7.6-nmol/100µL, 5.6 µL/min pump rate. Single Channel dialyser, 10 mm long, 0.5 mm wide, 0.3 mm high in stirred beaker of DI water Fraction Collector programed to rotate every 30 min. Set up in…
BSA Retention in Single Channel Dialyzer
Regarding the single channel dialyzer chip with 20-nm thick nano-porous silicon membrane: 10 mm long, 300 µm deep, 500 µm wide channels. Now that we’ve shown that a measurable quantity of urea is filtered out of DI water in one…
