Ct Value Cycle Threshold Copy Number Log Interpolator
Interpolate caller qualified standard-curve Ct knots in log10-copy space without extrapolation; does not invent a PCR calibration.
Description
Interpolate caller qualified standard-curve Ct knots in log10-copy space without extrapolation; does not invent a PCR calibration.
Copy-number interpolation uses a qualified standard curve rather than a universal Ct-to-copies factor. Both the calibration's scope and the logarithmic copy scale matter.
When to use this tool
Interpolate caller qualified standard-curve Ct knots in log10-copy space without extrapolation; does not invent a PCR calibration.
- Prepare the supplied ct, standardCts, standardLog10Copies, callerVerifiedSource, callerVerifiedContext, callerVerifiedAsOfDate fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter ct, standardCts, standardLog10Copies, callerVerifiedSource, callerVerifiedContext, callerVerifiedAsOfDate. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.log10Copies, result.copies. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Require source/context/date provenance and aligned standardCts/standardLog10Copies with at least two strictly increasing Ct knots. Locate ct within their inclusive range, interpolate log10 copies linearly between neighboring knots, and return that value plus 10 raised to it.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| ct | ct. | Finite number |
| standardCts | standard cts. | List of finite numbers; bounded by the operation |
| standardLog10Copies | standard log10 copies. | List of finite numbers; bounded by the operation |
| callerVerifiedSource | Source/edition identifier you supply for the evidence. | Nonblank text, at most 1,024 code units; not authenticated |
| callerVerifiedContext | Applicability, jurisdiction, device or scientific context you supply. | Nonblank text, at most 1,024 code units; not authenticated |
| callerVerifiedAsOfDate | Reference date supplied by you; retained with the result. | Valid Gregorian YYYY-MM-DD date; not proof of freshness |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.log10Copies | The log10 copies value under the stated formula or text convention. |
| result.copies | The copies value under the stated formula or text convention. |
{
"input": {
"callerVerifiedSource": "illustrative-qualified-reference/edition",
"callerVerifiedContext": "Illustrative independently checked topic-specific record, not an authoritative default.",
"callerVerifiedAsOfDate": "2026-01-01",
"ct": 20,
"standardCts": [
10,
20,
30
],
"standardLog10Copies": [
3,
2,
1
]
},
"output": {
"result": {
"log10Copies": 2,
"copies": 100
}
}
}Limitations and assumptions
- No extrapolation is allowed. The caller must order both arrays together by increasing Ct; the tool does not fit a regression, verify calibration, correct extraction efficiency or infer clinical viral load from an unqualified curve.
- Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
- Ordinary string lists have at most 128 entries of at most 128 code units each; numeric lists and matrices have separate bounded size checks. Nonfinite results and excessively large serialized outputs are rejected.
- Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.
Alternative or Complementary methods
Keep physical-particle counts, infectious assay units and observed sample proportions distinct. Use the original calibration, product instructions or validated assay method for the specific context; simple conversions and reference notes do not establish infectivity or clinical interpretation.
References
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