ResidualHostCellDNAqPCRChecker

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface and behaviour of ResidualHostCellDNAqPCRChecker for Residual Host Cell DNA qPCR Checker.

Domain limits and critical parameters

• ℹ️ Utility assesses residual host cell DNA content in recombinant and culture-based products according to WHO and FDA guidelines:
• • Critical Limit: < 10 ng per dose (for continuous cell lines).
• • qPCR Method Validation: Coefficient of determination (R²) ≥ 0.98, Amplification Efficiency 90-110%.
• • Control of Limit of Detection (LOD) and Quantification (LOQ).
• • Contamination check (NTC must be Undetermined).
• ⚠️ CRITICAL: Exceeding the 10 ng/dose limit is unacceptable due to potential oncogenic risk!
• Modern purification methods must reduce this level to trace amounts, controlled by highly sensitive PCR.
• ⚠️ CRITICAL:
• • 10 ng/dose Limit: Established by WHO as a safe threshold for most recombinant vaccines and proteins.
• • Primer Specificity: Primers must be specific only to the DNA of the given cell line.
• • Reagent Purity: All reagents must be certified "DNase-free".
• • Verification against global regulatory limits
• Critical parameters:
• • DNA per dose: < 10 ng
• • Standard Curve R²: ≥ 0.98
• 3. Interpretation: If result is < LOQ but > LOD, it is considered quantitatively uncertain, but qualitative presence should be noted.
• 4. Investigation: If limit is exceeded, check efficiency of purification steps (nuclease treatment, ultrafiltration).
• ⚠️ Note: For some new platforms (e.g., mRNA), requirements may vary, but the principle of minimizing host DNA remains the GMP gold standard.

URS — User Requirements Specification

input.csv contract

BatchNumber,ProductName,CellLine,MeasuredConcentration_ng_per_ml,DilutionFactor,DoseVolume_ml,LOD_ng_per_ml,LOQ_ng_per_ml,R_Squared,Efficiency_Percent,NTC_Result
DNA-CHO-2026-001,Monoclonal Antibody,CHO-K1,0.5,10.0,1.0,0.1,0.3,0.995,98.0,Undetermined
DNA-VERO-2026-002,Vaccine Inactivated,Vero,2.0,5.0,0.5,0.2,0.5,0.990,95.0,Undetermined
DNA-FAIL-2026-003,Recombinant Protein,HEK293,15.0,1.0,1.0,0.1,0.3,0.992,99.0,Undetermined

Input validation rules

FS — Functional Specification

Example output.json

{
  "utilityId": "residualhostcelldnaqpcrchecker",
  "utilityFolder": "ResidualHostCellDNAqPCRChecker",
  "package": "Vet",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "processedAtUtc": "2026-06-10T00:00:00Z",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "DNA-CHO-2026-001",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-001"
    },
    {
      "parameter": "ProductName",
      "value": "Monoclonal Antibody",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-002"
    },
    {
      "parameter": "CellLine",
      "value": "CHO-K1",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-003"
    },
    {
      "parameter": "MeasuredConcentration_ng_per_ml",
      "value": "0.5",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-004"
    },
    {
      "parameter": "DilutionFactor",
      "value": "10.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-005"
    },
    {
      "parameter": "DoseVolume_ml",
      "value": "1.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-006"
    },
    {
      "parameter": "LOD_ng_per_ml",
      "value": "0.1",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-007"
    },
    {
      "parameter": "LOQ_ng_per_ml",
      "value": "0.3",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-008"
    },
    {
      "parameter": "R_Squared",
      "value": "0.995",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-009"
    },
    {
      "parameter": "Efficiency_Percent",
      "value": "98.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-010"
    },
    {
      "parameter": "NTC_Result",
      "value": "Undetermined",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-011"
    }
  ],
  "criticalFindings": [],
  "warnings": [],
  "audit": {
    "inputHash": "sha256:<calculated at runtime>",
    "rulesVersion": "<utility executable version>",
    "documentation": "ResidualHostCellDNAqPCRChecker.documentation.html"
  }
}

Traceability matrix

IQ/OQ/PQ test scenarios

QA/QC and change control

• Do not rename columns without updating validator, documentation and test set.
• Retain input.csv, output.json, executable version and checksum.
• Before production use, perform IQ/OQ/PQ or equivalent CSV/CSA verification.
• Critical limits shall be verified against the approved specification, registration dossier and local SOPs.
• The utility provides structured QC decision support; final release decision remains with QA/QP and approved procedures.