ibidi Pump System
The cells were stressed by the abrupt tem-
perature change from being placed onto
the metal surface of the sterile working
bench.
Avoid placing slides directly onto metal surfaces. For
best results, place slides on the
, or a
Petri dish.
The cells were stressed, because the con-
nection step took too long.
Connecting the slides is time critical. Work as quickly
as possible and make sure to have everything on hand
before the connection step.
The cells were not healthy.
Try another lot or passage of cells. Primary cells espe-
cially are very variable in their fitness.
10.2.3
Cells Detach under Flow Conditions
Issue:
Cells detach after starting the flow experiment.
Possible Cause
Solution
The shear stress was applied too fast.
Allow the cells to become accustomed to flow by start-
ing with a very low shear stress and increase it step by
step (see
The applied shear stress was too high.
Check publications and literature for recommenda-
tions on suitable shear stress values for your cells and
your application
in vitro
. If necessary, decrease the
flow rate.
The cells were not healthy.
Try another lot or passage of cells. Primary cells espe-
cially are very variable in their fitness.
The cell number in the slide was too low.
Cells could not form a confluent layer
and were detached from the surface.
Seed more cells. Before starting the flow, the cells
should be nearly confluent.
The coating was not stable and was
washed away by the flow.
Check the coating with fluorescence staining before
and after applying flow. Try alternative coatings or
the ibiTreat surface.
There was too much evaporation through
the tubing and filters of the Perfusion Set,
which increased the salt concentration in
the medium.
Check if the volume of the medium decreased. In-
crease the humidity in the incubator. Open the incuba-
tor as little as possible. The humidity recovery inside
the incubator may take up to 30 minutes or even sev-
eral hours.
The CO
2
concentration in the incubator
was too low, and the medium was not
equilibrated to a neutral pH.
Make sure the CO
2
supply is sufficient to equilibrate
the pH of the medium.
10.3
Imbalanced Medium
If the flow rate differs in the two switching states (running from left to right or running from right to
left), more and more medium is accumulating in one of the reservoirs. In the worst case, the medium
reaches the filter on top and the filter gets clogged.
Version 2.6 (May 12, 2022)
74
Instruction Manual
