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. Ethanol was pumped through the chip for 1 hour, then degassed PBS was pumped for…
In researching for the paper for Advances in Chronic Kidney Disease (ACKD) I’ve run across some interesting papers. Here is one describing a proposed Human Nephron Filter… Human nephron filter proposed by Nissenson1 (1) 1Division of Nephrology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA This imagined device was…
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 experiments). We expect (without Serum) a 30% extraction so from 0.5 mM urea to 0.35…
pnc-Si chips prewetted with PBS then incubated with fetal bovine serum (unknown molarity) for 2 hours under refrigerated conditions. Thoroughly rinsed with reaction buffer (perfused 5 times). TRITC (2 mg/mL) added to dry chips and incubated at room temperature for one hour. Then rinsed once with reaction buffer then rinsed thoroughly with distilled de-ionized (DDI)…
The last of the larger windowless pnc-Si chips were sent to both Adarza and Dr. Shestopalov’s lab for functionalization. Adarza returned chips with PEG-1 and PEG-2 (different rounds of processing) with both 2 hours and 16 hour treatments. They also returned a set treated with an alcohol leaving group ,ethanolamine (EA). They did also supply…
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 accidental contact between the PDMS and membrane.
Chips of pnc-Si were funtionalized at Adarza. They returned four groups of chips. Ethanolamine, Amino PEG-1, Inactivated sLinker, and Amino PEG-2. These were all incubated with PBS and 5-mg/mL f-BSA (2:3) in a humid refrigerated dish. The samples were rinsed in PBS then DI water and dried with filtered compressed air. The measurements were taken…
Katia in Dr. Shestopalov’s Lab functionalized some pnc-Si windowless chips. The process she follows is shown in Figure 1. She provided chips at various stages of the process. “Grignard”, “Diazirine”, and “PEG”. After functionalization, the chips were wetted with 20 µL of 1:1 pbs then 40 µL of 5 mg/mL f-BSA was added. The…
Samples of pnc-Si, 5.5 mm x 5.5 mm, were functionalized at Adarza and incubated with fluorescein conjugated BSA. Wells were formed in PDMS to hole fluid above the samples. Samples were wetted with PBS then f-BSA, 5 mg/mL, was added. The samples were placed in petri dishes with DI water soaked Kim wipes; the petri…
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 from the stacked levels of chips.