Antibiotic Dilution / MIC Reference Calculator (education)

Inspectable records

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

t5-187

Ledger rows

1

No ledger note is attached.

Review findings

The mathematical formula is correct under the stated 2-fold serial-dilution assumptions. NEEDS_REVIEW is required because the C0-versus-C1 output convention and the physical 1:2 dilution procedure are unspecified. The existing educational, lab-planning, protocol-verification, and not-a-treatment-tool labeling is appropriate.

Formula and scope findings

• C_n=C0/2^n is the standard formula for a serial 2-fold dilution only when every step produces a 1:2 dilution, such as equal volumes of sample and diluent; that operational constraint is not stated.
• The spec does not define whether the output series includes the undiluted stock C0 or only diluted wells/tubes C1 through Cn.
• This computes nominal concentrations for MIC-test setup but does not determine an MIC endpoint; the output claim should not imply that it performs MIC interpretation.

Unit assumptions

• C0 and every Cn use the same concentration unit unless an explicit conversion is requested.
• The dilution factor 2 is dimensionless; each step halves the concentration.
• For the unit-conversion test, 1 mg/mL = 1000 µg/mL.
• number of dilution steps must be a finite, nonnegative integer; the test vectors define outputs as C0 through Cn.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

At 1075 dilution steps with stock concentration 1, the mathematical result is approximately 2.4703282292062327e-324, but plain JavaScript arithmetic underflows it to 0. The specification also leaves integer-step validation and series indexing/unit conventions implicit.

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": {
    "stock_concentration": 64,
    "concentration_unit": "µg/mL",
    "dilution_steps": 5,
    "output_convention": "C0 through Cn"
  },
  "expected_outputs": {
    "concentrations_ug_per_mL": [
      64,
      32,
      16,
      8,
      4,
      2
    ]
  },
  "working": "C0 = 64 µg/mL; C1 = 64/2 = 32 µg/mL; C2 = 32/2 = 16 µg/mL; C3 = 16/2 = 8 µg/mL; C4 = 8/2 = 4 µg/mL; C5 = 4/2 = 2 µg/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