Logos Quantom Tx - Protocols and Parameters; Protocol Parameters

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5. Protocols
Protocol Parameters
Counting parameters
Counting parameters can be adjusted to customize protocols for specific bacteria.
Parameter
Range
DEFAULT
Dilution Factor
1-20,000
2
Min Fluorescent Object Size (µm)
0.3-49
0.3
Max Fluorescent Object Size (µm)
0.4-50
50
Roundness (%)
0-100
30
Declustering Level
0-10
7
Detection Sensitivity
0-9
0
*The DEFAULT protocol cannot be modified or deleted.
Dilution factor
The dilution factor must be set properly prior to counting to ensure accuracy when
calculating the total cell concentration.
Final sample volume*
Dilution factor = ------------------------------------------ .
Bacterial suspension volume
*final sample volume = bacterial suspension volume + reagents volume
For users handling highly dense cultures, serial dilutions and several counts with
appropriately adjusted dilution factors will be necessary.
Fluorescent object size
Fluorescent object size measures the diameter of the fluorescent signal from the nucleic
acid stains. This does not correspond to the physical size of the cell. This can be adjusted
in 0.1 µm increments between 0.3-1.0 µm and in 1 µm increments between 1-50 µm.
Roundness
Set roundness according to the shape of sample. The counting algorithm will include
objects that are less round at lower values, which will include bacterial shapes such as
bacilli and vibrio. Higher values will include rounder shapes such as cocci.
Declustering level
The declustering function allows for the efficient detection of a cells that may grow in
clusters or chains. Higher values will lead to a higher sensitivity to clusters.
Detection sensitivity
Detection sensitivity refers to the sensitivity of fluorescence detection. Higher values
detect fainter signals from weakly stained cells or smaller sample sizes but can also
increase noise.