Petroff-Hausser Direct Count Conversion Calculator
Actual Petroff-Hausser observed square counts with actual chamber geometry, not assumed generic hemocytometer depth; viable fraction/detection artifacts omitted.
Description
Petroff-Hausser Direct Count Conversion Calculator: return cells per ml.
A counting chamber samples cells in a known microscopic volume. Converting that count to cells per milliliter requires both the counted square area and the chamber depth.
This tool returns cells per ml. Use the stated units and model convention when interpreting these fields.
When to use this tool
Use this tool when the supplied inputs match the specific operation described above and you need a repeatable result under its stated convention.
- Check the supported input and output contract against an existing calculation or observation.
- Use the complete example to confirm units, selector spelling and result interpretation.
How to use the tool and how it works
- Enter every field in the input table using the stated units and the exact supported selector spelling where applicable.
- Run the tool. Correct input errors before interpreting an output.
- Read the result fields below; use accompanying flags and the stated sign, boundary or model convention when interpreting a number.
Average the supplied square counts, multiply by 1000 and the dilution divisor, and divide by square area times chamber depth. The factor 1000 converts cubic millimeters to milliliters.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| cellsPerCountedSquare | Cells per counted square. | List of finite numbers |
| actualSquareAreaMm2 | Actual square area mm2. Square millimeters. | Finite number; greater than zero |
| actualChamberDepthMm | Actual chamber depth mm. Millimeters. | Finite number; greater than zero |
| dilutionDivisor | Dilution divisor. | Finite number; greater than zero |
| Output field | Interpretation |
|---|---|
| result | Object containing the following named result fields. |
| result.cellsPerMl | Cells per ml; use the stated units and sign convention. |
{
"input": {
"cellsPerCountedSquare": [
10,
20
],
"actualSquareAreaMm2": 0.0025,
"actualChamberDepthMm": 0.02,
"dilutionDivisor": 1
},
"output": {
"result": {
"cellsPerMl": 300000000
}
}
}Limitations and assumptions
- A direct cell count does not distinguish viable from nonviable cells or correct for clumps and sampling bias.
- Every declared field is required and unexpected fields are rejected. Numeric inputs must be finite; input errors are distinct from a valid false result or an explicitly qualified output.
- Extremely large inputs and nonfinite or excessively large outputs are rejected. List positions reported by the tool use zero-based indices unless stated otherwise.
Alternative or Complementary methods
Check the underlying observations, units and conventions independently before using the result in a larger workflow. The tools listed below address nearby tasks; compare their inputs and scope before substituting one for this operation.
References
Similar or alternative tools
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