Liquid
biopsy targets rare cells that overexpress disease-specific
membrane markers and capture these cells via immunoaffinity. The diagnosis
efficiency of liquid biopsy can be impaired by the presence of healthy
adherent cells also expressing the same biomarkers. Here, we investigated
the effect of settling times and rinsing flow rates on the efficiency
of EpCAM-based immunocapture using both simulation and experiments
with three different cell types. Cell-surface adhesion forces and
shear rates were calculated to define the range of rinsing flow rates
to test experimentally. Healthy adherent cells did not adhere to blocked
immunofunctionalized surfaces within the timeframe of the experiment;
however, healthy EpCAM positive cells did bind to the surface to some
extent. The greatest difference in capture efficiency was obtained
using a high rinsing flow rate of 25 mL/min following 40 min static
incubation, indicating that optimizing rinsing flow rates could be
a viable option to capture, more specifically, cancer cells overexpressing
EpCAM.