Cell Counting / Hemocytometer Calculator

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

t5-163

Ledger rows

1

No ledger note is attached.

Review findings

The concentration formula is conditionally standard, but the specification needs explicit chamber geometry, dilution-factor convention, volume units, total-cell formula, and viability formula before implementation. The educational and not-medical-advice label is appropriate but does not replace these technical assumptions.

Formula and scope findings

• The cells/mL formula is standard only when the counted square has a volume of 0.1 µL, as in the standard Neubauer hemocytometer; the chamber type and square dimensions are not specified.
• The formula for total cells is omitted. It should be total cells = cells/mL × total volume in mL.
• The formula for viability percentage is omitted despite viability being listed as an output. The standard formula is viability % = live cells ÷ (live cells + dead cells) × 100.
• The meaning of dilution factor is ambiguous: it must be the reciprocal of the sample fraction, so a 1:1 sample-to-diluent mixture has dilution factor 2, not 1.
• The meaning of avg_count is not explicitly defined; it should be the arithmetic mean of valid square counts, typically sum of counts divided by number of squares.

Unit assumptions

• The factor 10^4 assumes a standard hemocytometer counting square of 1 mm × 1 mm × 0.1 mm, with concentration reported in cells/mL.
• Dilution factor is dimensionless and represents the reciprocal of the fraction of original sample in the counted suspension.
• Total volume must be supplied in mL before calculating total cells; volumes in µL require conversion using 1000 µL = 1 mL.
• Cell counts are nonnegative counts, and number of counted squares is a positive integer.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The instrument has an undefined-result failure when number_of_squares is zero and a potentially 100-fold numerical discrepancy when the dilution notation 1:10 is interpreted using the wrong convention.

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": {
    "counts_per_square": [
      84,
      91,
      88,
      87
    ],
    "number_of_squares": 4,
    "dilution_factor": 2,
    "total_volume_mL": 5
  },
  "expected_outputs": {
    "cells_per_mL": 1750000,
    "total_cells": 8750000
  },
  "working": "Average count = (84 + 91 + 88 + 87) ÷ 4 = 350 ÷ 4 = 87.5. Cells/mL = 87.5 × 2 × 10,000 = 1,750,000 cells/mL. Total cells = 1,750,000 × 5 mL = 8,750,000 cells."
}

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