3. Detect and segment spot on the ROS detection channel in the
cytoplasm as region of interest (ROI), using a “spot” detection
algorithm similar to the one used for mycobacteria.
4. Measure intensity properties (Mean, Max, Sum) and ROS area
(in pixels) for each ROS spot detected.
5. Calculate all host-related parameters for all cells. Define
“infected” and “non-infected” cell populations and (1) number
of ROS spots and (2) ROS area per cell for the two distinct
cellular populations.
3.31 Image-Based
Analysis
for Quantification
of Oxidative Stress by
Intracellular Nitric
Oxides (NO) Detection
[19]
1. Proceed first to cell and mycobacteria detection and quantification (see steps 1–8 in Subheading 3.26).
2. Define a manual threshold corresponding to the basal level of
NO, using “non-infected” cell population, “NO inhibitor”
and “NO inducer” controls to set intensity thresholds.
3. Detect and segment round shaped spots with a given maximum
radius on the NO detection channel in the cytoplasm as region
of interest (ROI), using a “spot” detection algorithm similar to
the one used for mycobacteria.
4. Measure intensity properties (Mean, Max, Sum) and NO area
(in pixels) for each NO spot detected.
5. Calculate all host-related parameters for all cells
(corresponding to single cell analysis). Define “infected” and
“non-infected” cell populations and (1) number of NO spots
and (2) NO area per cell for the two distinct cellular
populations.
3.32 Image-Based
Analysis
for Quantification
of Zinc Poisoning [10]
1. Proceed first to cell and mycobacteria detection and quantification (see steps 1–8 in Subheading 3.26).
2. Define a manual threshold corresponding to the basal level of
zinc, using “non-infected” cell population, “non-infected cell”
and “infected cell” controls to set intensity thresholds.
3. Detect and segment metal deposits, similarly to the bacteria
segmentation, using a “spot” detection algorithm.
4. Calculate the co-localization between bacteria and metal
deposits using the Mander’s Coefficient, yielding “FluoZin-3
positive” and “negative” bacterial populations.
5. Calculate all host-related parameters. Define “infected” and
“non-infected” cell populations and further cluster according
to the presence of FluoZin-3 deposits (FluoZin-3 positive
versus negative mycobacteria).
6. Image and use the same analysis parameters to detect intracellular Zinc indicator controls (range from 10 to 100 μM).
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