In order to address the fluctuations in the clearance data at the beginning of the long term treatment previous post The new protocol is as follows: 1. An inspected single slot dialysis chip is clamped into an acrylic fixture holding…
Author: Dean Johnson
Dr. Johnson is a Research Assistant Professor in Nephrology who was awarded an R01 in 2020. He earned his Ph.D. in Microsystems Engineering from RIT and is currently working on hemodialysis devices based on the ultrathin nanoporous membranes developed earlier by this group.
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…
Paper for Review: Nanoporous Parylene for Ultrafiltration
If you know me at all, you know I enjoy nothing more than ultrafiltration and Parylene-C deposition. Now these activities are combined into one device to improve the biocompatibility (platelet activation and adhesion) of nanoporous membranes. In this letter, polyethersulfone…
Posted in NRG
Serum adsorption, detection, TRITC, TECAN, Fluorecence 'Scope
These Adarza chips were pre wetted with PBS then incubated with fetal bovine serum (FBS) overnight in the refrigerator then rinsed. TRITC (2 mg/mL) added to chips and incubated at room temperature for one hour. Then rinsed once with…
Posted in NRG
TRITC tagging of Fetal Bovine Serum, TECAN v ImageJ measurements
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…
Comparitive Functionalization of pnc-Si measured with f-BSA fluorescence intensity
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…
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…
f-BSA Adsorption on Adarza functionalized pnc-Si chips
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…
f-BSA adsorption on Functionalized pnc-Si (Shestopalov Lab)
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…
f-BSA adsorption pnc-Si
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.…
