Source: https://guthlabs.ai/docs/instruments/culture-media-buffer-recipe-scaler/

instrument / verified-clean

# Culture Media / Buffer Recipe Scaler

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/culture-media-buffer-recipe-scaler/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/culture-media-buffer-recipe-scaler/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/culture-media-buffer-recipe-scaler/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/culture-media-buffer-recipe-scaler/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Biology, Medicine & Pharmacology (educational estimates only — every panel labeled not-medical-advice)

**Tranche**: tranche-5

**Evidence ID**: t5-169

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The exact ambiguity requiring review is that the specification does not state volume units or require recipe_volume and target_volume to be dimensionally compatible. The honest label is appropriate: this is an arithmetic scaling aid and should not be presented as recipe validation or medical advice.

### Formula and scope findings

- The formula is correct for linear scaling when recipe_volume and target_volume use the same units and recipe amounts are specified for the recipe's final volume.

- The specification does not define constraints for negative amounts or volumes, nor whether target_volume=0 is permitted.

- The formula does not account for non-linear preparation effects, stock-solution concentrations, density changes, evaporation, or practical rounding; it is only a proportional arithmetic scaler.

### Unit assumptions

- recipe_volume and target_volume must use identical units, or one must be explicitly converted before calculating the ratio.

- Each recipe component amount is scaled independently and retains its original unit, such as grams, milligrams, milliliters, or moles.

- The recipe amount represents the quantity required in the stated recipe final volume.

- For a final-volume recipe, component quantities are assumed to scale linearly with volume.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

A zero recipe volume produces undefined scaling and should be rejected. The specification also leaves unit normalization unspecified, allowing a severe error: 5 g is correct for 1 L to 500 mL, whereas raw numeric division would produce 5000 g.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "recipe_amounts": {
      "NaCl_g": 10,
      "glucose_g": 5,
      "water_mL": 1000
    },
    "recipe_volume_L": 1,
    "target_volume_L": 2.5
  },
  "expected_outputs": {
    "scaled_amounts": {
      "NaCl_g": 25,
      "glucose_g": 12.5,
      "water_mL": 2500
    }
  },
  "working": "Scale factor = target_volume / recipe_volume = 2.5 L / 1 L = 2.5. NaCl = 10 g × 2.5 = 25 g. Glucose = 5 g × 2.5 = 12.5 g. Water = 1000 mL × 2.5 = 2500 mL."
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`