Cedex HiRes - Description of the Individual Operator Parameters

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10.5.8. Description of the Individual Operator Parameters
ClassificationBias
Range: [-20, 20], Default: 0, Unit: [absolute value].
This parameter influences the classification behavior of viable and dead cells. Since dying cells of different cell
lines absorb Trypan Blue differently, dead cells can be variably stained. Positive values of this parameter tend to
let the operator recognize more living cells and less dead cells. Negative values cause the opposite effect, with
more dead cells and less living cells being recognized. This parameter’s default setting is optimized for dark-
looking dead cells and living cells with a bright cell interior.
An example of a possible need for a change to a more negative value would be a cell line that poorly absorbs
Trypan Blue when dead or dying. In the default setting with the value 0, these cells would still often be recognized
as living. If the value is changed to negative value, however, more dark objects would be counted as dead cells.
The viability recorded would, therefore, be reduced.
CMinSize [µm] (Cells’ Minimum Size)
Range: [0, 100], Default: 7, Unit: [micrometer]
This parameter determines the minimum cell size (diameter values measured in micrometer). It serves the
purpose of discerning debris from cells.
LCAppearance (Live Cells’ Appearance)
Range: [-10, 10], Default: 0, Unit: [absolute value]
This parameter influences the recognition of living cells. When the value of this parameter is set high, contrast-
weak objects are also counted as living cells provided they additionally fulfill the size criterion. The lower this
value is set, the more contrast an object must have for it to be counted as a viable cell.
If the value is changed to positive, shadowy and greyish objects are increasingly counted as living cells. Such a
change can be sensible if, for example, the optical image shows little contrast due to the structure of the medium
or of the cells in the medium.
DCAppearance (Dead Cells’ Appearance)
Range: [-10, 10], Default 0, Unit [absolute measure]
This parameter influences the recognition of dead cells. If the value is set high, contrast-weak objects are also
counted as dead cells as long as they additionally fulfill the size criterion. The lower this value is set, the sharper
the contrast an object must have in order to be counted as a dead cell.
In standard situations, a change of this parameter can result in the labeling of debris as cells.
Administrator Functions
Adjustment of the Image Analysis using the Live Operator