Control Derived Biofilm Bands

Classify crystal-violet biofilm OD using a supplied control-SD cutoff and conventional 1×/2×/4× bands; these are assay bands, not clinical severity.

Description

Crystal-violet biofilm measurements can be grouped relative to a negative-control cutoff.

Crystal-violet biofilm measurements can be grouped relative to a negative-control cutoff. Control variability and the selected SD multiplier determine that cutoff, while the bands describe the assay rather than disease severity.^[1]

Classify crystal-violet biofilm OD using a supplied control-SD cutoff and conventional 1×/2×/4× bands; these are assay bands, not clinical severity.

When to use Control Derived Biofilm Bands

Use this tool to classify crystal-violet biofilm OD using a supplied control-SD cutoff and conventional 1×/2×/4× bands; these are assay bands, not clinical severity.

Prepare the sample, count, growth or assay measurements requested by this tool. Confirm units, sampling periods and reporting bases; supply independently established comparison criteria where requested.

How to use Control Derived Biofilm Bands and understand its results

Prepare the sample, count, growth or assay measurements requested by this tool. Confirm units, sampling periods and reporting bases; supply independently established comparison criteria where requested.
Enter sampleOds, negativeControlOds, cutoffSdMultiplier using the field table and calculation rules, then run the tool.
Read controlCutoffOd, formationBands. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
sampleOds	Sample ods	list of number	Required
negativeControlOds	Negative control ods	list of number	Required
cutoffSdMultiplier	Cutoff sd multiplier	number; minimum: 0	Required

Supply nonempty nonnegative sample ODs, at least two nonnegative control ODs and a nonnegative SD multiplier. The cutoff must be positive. The tool uses n−1 control SD and labels ≤cutoff none, ≤2cutoff weak, ≤4cutoff moderate and higher strong, with a small floating-point boundary allowance.

cutoff=controlMean+multiplier × sampleSD; bands use 1×, 2× and 4×cutoff

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
controlCutoffOd	Control cutoff od	number
formationBands	Formation bands	list of string

json

{
  "input": {
    "sampleOds": [
      0.1,
      0.3,
      0.6
    ],
    "negativeControlOds": [
      0.08,
      0.1,
      0.12
    ],
    "cutoffSdMultiplier": 3
  },
  "output": {
    "controlCutoffOd": 0.15999999999999998,
    "formationBands": [
      "none",
      "weak",
      "moderate"
    ]
  }
}

Limitations and assumptions

These are conventional relative assay bands, not clinical severity or a viability measure. Controls, staining protocol and blank handling are supplied; a zero cutoff is an input error.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Biofilm Biomass Normalized Adhesion: Normalize blank-corrected crystal-violet stain OD by matched biomass OD to compare adhesion among cultures. For a complementary task, use Biofilm Eradication Endpoint: Find the lowest observed biofilm exposure concentration meeting a supplied post-exposure recovery criterion; units and protocol must be consistent.

References

Control Derived Biofilm Bands — tool.io

Similar or alternative tools

Biofilm Biomass Normalized Adhesion
Normalize blank-corrected crystal-violet stain OD by matched biomass OD to compare adhesion among cultures.
Biofilm Eradication Endpoint
Find the lowest observed biofilm exposure concentration meeting a supplied post-exposure recovery criterion; units and protocol must be consistent.