Osmotic Agents for Preventing Ultrafiltration During Microdialysis
Purpose
This article explains why serum albumin is a better alternative to dextran to prevent ultrafiltration in mircrodialysis.
Solution
Dextran vs BSA:
Most of our users add 0.15% serum albumin as an osmotic agent as opposed to dextran, for several reasons:
-BSA is a better blocking and carrier agent than dextran for preventing binding of peptides and proteins to plastic surfaces (probe, tubing, swivel, sample storage tubes).
-BSA acts as a sacrificial substrate for proteases in the perfusate.
-Dextran can cause a strong immune response if it leaks out of the probe. With 100 kDa MWCO probes, if you are going to use dextran, I would suggest using Dextran 500:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004663/
However, the presence of BSA makes LC-MS analysis much more difficult