# qPCR Relative-Expression Calculator (Pfaffl Method)

> qPCR Relative-Expression Calculator (Pfaffl Method) is a paid API for AI agents from www.mahastrategies.com, paid per call via x402, $0.010043/call, status unknown (last checked 2026-10-15).

Calculates a Pfaffl expression ratio from target and reference gene Ct values and amplification efficiencies, requiring a declared stable reference gene.

## Facts

- Endpoint: POST https://www.mahastrategies.com/api/v1/compute/biology/qpcr-relative-expression?utm_source=zero.xyz
- Price: $0.010043/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/qpcr-relative-expression-calculator-pfaffl-method-85dc7738
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rPX4-MA_Fn6AgZqFLeM0n

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability qpcr-relative-expression-calculator-pfaffl-method-85dc7738 -d '<json body>'
```

Example prompt: Calculate the Pfaffl relative expression ratio for my qPCR experiment: target gene sample Ct is 22.3, target control Ct is 28.1, target efficiency is 1.95; reference gene sample Ct is 19.4, reference control Ct is 19.6, reference efficiency is 1.98 — the reference gene is confirmed stable, and this is synthetic data.

## When to prefer this

Use this endpoint when you need a programmatic, efficiency-corrected Pfaffl relative expression ratio from raw Ct values without manual spreadsheet calculations. Prefer it over delta-delta Ct approaches when amplification efficiencies differ from 100% and must be accounted for. Best suited for automated qPCR analysis pipelines where a stable reference gene is already confirmed.

## Known failure modes

- Missing or false referenceStable flag — endpoint requires reference gene to be declared stable
- Out-of-range or invalid Ct/efficiency values outside expected biological bounds
- Missing required fields such as targetSampleCt, referenceControlCt, or efficiencies
- Invalid dataClass enum value (must be 'public' or 'synthetic')
- Payment failure via x402 protocol preventing request processing
- Server error or timeout during computation

## How this service works

Calculate a Pfaffl expression ratio from supplied Ct values and amplification efficiencies; require a declared stable reference. No diagnostic interpretation. New modular adapter: retained result recovery for 24 hours, minimal receipt metadata for 90 days. Existing live route unchanged.

## Output

Returns a computed Pfaffl expression ratio derived from the supplied Ct values and amplification efficiencies for both target and reference genes. Results are retained for 24 hours; minimal receipt metadata is retained for 90 days. No diagnostic interpretation is provided.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "dataClass": {
   "enum": [
    "public",
    "synthetic"
   ],
   "type": "string"
  },
  "targetSampleCt": {
   "type": "number",
   "maximum": 1000000000000,
   "minimum": -1000000000000
  },
  "referenceStable": {
   "type": "boolean"
  },
  "targetControlCt": {
   "type": "number",
   "maximum": 1000000000000,
   "minimum": -1000000000000
  },
  "targetEfficiency": {
   "type": "number",
   "maximum": 1000000000000,
   "minimum": -1000000000000
  },
  "referenceSampleCt": {
   "type": "number",
   "maximum": 1000000000000,
   "minimum": -1000000000000
  },
  "referenceControlCt": {
   "type": "number",
   "maximum": 1000000000000,
   "minimum": -1000000000000
  },
  "referenceEfficiency": {
   "type": "number",
   "maximum": 1000000000000,
   "minimum": -1000000000000
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/qpcr-relative-expression-calculator-pfaffl-method-85dc7738/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.mahastrategies.com](https://www.zero.xyz/host/www.mahastrategies.com/llms.txt)