Acea RTCA SP Instrument - The Cell Index Signal Decreases with Time, but There was no Compound Added. Why; The Cell Index Signal Is Signifi Cantly Higher than Usual. Why

56
RTCA SP Instrument Operator’s Manual
E
E
1.6 The Cell Index signal decreases with time, but there was
no compound added. Why?
Remove the E-Plate 96 from the incubator and check the cell status (cell number, cell
distribution and morphology) under a microscope. Check for the following:
 Contamination resulting in cells dying.
 Culture media that is too old to support the cell growth, because the experiment is too
long.
 Culture media quantity is insu cient to support cell growth, due to too much
evaporation.
 Maybe there is something wrong with the incubator. One likely symptom of incubator
problems is that the cell index is lower on edge wells than on the center wells, or the
cell index drops to nearly zero faster on the edges than the center wells.  e problems
with incubators may include CO
2
level, temperature control, humidity control and
certain chemicals released from the incubator. We have encountered several instances
where the incubator itself was presenting to be “toxic” or a ecting cell growth. Some-
times a simple but thorough cleaning of the incubator interior may be su cient to
solve the problems. Alternatively, simply running the experiment in another incubator
may solve the problems.
Please make sure, when removing the E-Plate 96 from the incubator, that the instrument
is not performing a measurement. If the instrument is waiting for next sweep, make sure
that you have enough time to check the cells under a microscope. If you do not have time,
you may have to stop the current step and then take the device out of the incubator for
assessment.  en Continue the experiment a er putting the E-Plate 96 back in.
1.7 The Cell Index signal is signifi cantly higher than usual.
Why?
Remove the E-Plate 96 from the incubator and check the cell status (cell number, cell
distribution and morphology) under a microscope. It is possible that the initial seeding
number was high.
Please make sure, when removing the E-Plate 96 from the incubator, that the instrument
is not performing a measurement. If the instrument is waiting for next sweep, make sure
that you have enough time to check the cells under a microscope. If you do not have time,
you may have to stop the current step and then take the device out of the incubator for
assessment.  en Continue the experiment a er putting the E-Plate 96 back in.
Troubleshooting
The Cell Index signal decreases with time, but there was no compound added. Why?
56
RTCA SP Instrument Operator’s Manual
E
E
E
E
E
E
E
E
E
1.6 The Cell Index signal decreases with time, but there was
no compound added. Why?
Remove the E-Plate 96 from the incubator and check the cell status (cell number, cell
distribution and morphology) under a microscope. Check for the following:

Contamination resulting in cells dying.

Culture media that is too old to support the cell growth, because the experiment is too
long.

Culture media quantity is insu cient to support cell growth, due to too much
evaporation.

Maybe there is something wrong with the incubator. One likely symptom of incubator
problems is that the cell index is lower on edge wells than on the center wells, or the
cell index drops to nearly zero faster on the edges than the center wells.  e problems
with incubators may include CO
2
level, temperature control, humidity control and
certain chemicals released from the incubator. We have encountered several instances
where the incubator itself was presenting to be “toxic” or a ecting cell growth. Some-
times a simple but thorough cleaning of the incubator interior may be su cient to
solve the problems. Alternatively, simply running the experiment in another incubator
may solve the problems.
Please make sure, when removing the E-Plate 96 from the incubator, that the instrument
is not performing a measurement. If the instrument is
waiting for next sweep
, make sure
that you have enough time to check the cells under a microscope. If you do not have time,
you may have to stop the current step and then take the device out of the incubator for
assessment.  en
Continue
the experiment a er putting the E-Plate 96 back in.
1.7 The Cell Index signal is signifi cantly higher than usual.
Why?
Remove the E-Plate 96 from the incubator and check the cell status (cell number, cell
distribution and morphology) under a microscope. It is possible that the initial seeding
number was high.
Please make sure, when removing the E-Plate 96 from the incubator, that the instrument
Please make sure, when removing the E-Plate 96 from the incubator, that the instrument
is not performing a measurement. If the instrument is
waiting for next sweep
waiting for next sweep
, make sure
that you have enough time to check the cells under a microscope. If you do not have time,
that you have enough time to check the cells under a microscope. If you do not have time,
you may have to stop the current step and then take the device out of the incubator for
you may have to stop the current step and then take the device out of the incubator for
assessment.  en
Continue
the experiment a er putting the E-Plate 96 back in.
the experiment a er putting the E-Plate 96 back in.
Troubleshooting
The Cell Index signal decreases with time, but there was no compound added. Why?