Gradient MIC Upper Step

Round a gradient-strip MIC intersection upward to a supplied reportable dilution series; no clinical breakpoint is embedded.

Description

Gradient-strip MIC readings may fall between reportable dilution steps.

Gradient-strip MIC readings may fall between reportable dilution steps. Selecting the next supplied step upward preserves the chosen reporting series instead of silently rounding downward.^[1]

Round a gradient-strip MIC intersection upward to a supplied reportable dilution series; no clinical breakpoint is embedded.

When to use Gradient MIC Upper Step

Use this tool to round a gradient-strip MIC intersection upward to a supplied reportable dilution series; no clinical breakpoint is embedded.

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 Gradient MIC Upper Step 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 intersectionConcentration, reportableConcentrations using the field table and calculation rules, then run the tool.
Read reportedMic, roundedUp, leftCensored. 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
intersectionConcentration	Intersection concentration	number	Required
reportableConcentrations	Reportable concentrations	list of number	Required

Enter a positive intersection and a nonempty strictly increasing positive reportable series in one unit. The tool selects the first step at least as large, reports whether it increased the value, and marks leftCensored if the reading is strictly below the first step. Above-range readings are errors rather than capped values.

Sequences checked for increasing order must be nonempty and strictly increasing; additional calculation rules may require more samples.

reportedMIC = first reportable concentration ≥ intersection

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

Output field	Meaning	Value type
reportedMic	Reported mic	number
roundedUp	Rounded up	boolean
leftCensored	Left censored	boolean

json

{
  "input": {
    "intersectionConcentration": 1.5,
    "reportableConcentrations": [
      0.5,
      1,
      2,
      4
    ]
  },
  "output": {
    "reportedMic": 2,
    "roundedUp": true,
    "leftCensored": false
  }
}

Limitations and assumptions

The series is caller-supplied and no clinical breakpoint is applied. It does not inspect a strip, assess ellipse quality or infer an endpoint above the provided range.

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. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Growth Inhibition MIC Endpoint: Derive the observed MIC from a monotone dilution-growth series, preserving below- and above-range censoring. For a complementary task, use Supplied Disk Zone Interpretation: Apply caller-supplied disk-diffusion zone breakpoints; I retains the supplied classification scheme and is not universally interpreted as intermediate.

References

Gradient MIC Upper Step — tool.io

Similar or alternative tools

Growth Inhibition MIC Endpoint
Derive the observed MIC from a monotone dilution-growth series, preserving below- and above-range censoring.
Supplied Disk Zone Interpretation
Apply caller-supplied disk-diffusion zone breakpoints; I retains the supplied classification scheme and is not universally interpreted as intermediate.