ControlPartitionTrendChecker

Control Partition Trend

Liquid Biopsy жидкостная биопсия cfDNA ctDNA CTC exosomes NGS qPCR

Utility description: Control Partition Trend

Control Partition Trend Checker — ddPCR Partition Quality Monitoring

ℹ️ Utility performs specialized QC monitoring for digital PCR according to MIQE-dPCR and CLSI MM26:
• Partition Yield: Control of total valid droplets/wells — direct indicator of generator health.
• Positive Fraction Stability: Tracking of positive partition fraction to detect reaction drift.
• Cluster Separation: Assessment of distance between positive and negative clusters in amplitude space.
• Rain Fraction: Monitoring of intermediate events that complicate gating and reduce accuracy.
• Concentration Accuracy: Verification of measured concentration against control material target value.

⚠️ IMPORTANT:
• In ddPCR, partition quality matters more than in qPCR: poor droplets = systematic quantification error.
• Droplet generator degradation often occurs gradually and invisibly without trend analysis.
• High "rain" may indicate master mix, primer, or thermocycling issues.

Usage:
ControlPartitionTrendChecker.exe → demo mode (console output)
ControlPartitionTrendChecker.exe input.csv output.json → evaluate your data

Input format:
ControlLot,TargetName,RunDate,TotalPartitions,MinPartitions,PositiveFraction,ExpectedPositiveFraction,PosClusterAmplitude,MinPosAmplitude,NegClusterAmplitude,MaxNegAmplitude,RainFraction,MaxRainFraction,MeasuredConcentration_copies_uL,TargetConcentration_copies_uL,ConcentrationTolerance_Percent

Example:
QC-LOT-A,RNase_P,2026-06-01,18500,10000,0.14,0.15,5200,3000,180,500,0.02,0.05,48.5,50.0,25

📍 Scope of Application (Usage Where):
• Clinical ddPCR Laboratories: Daily QC before patient sample runs.
• Liquid Biopsy: Guaranteeing assay sensitivity for rare mutations.
• ddPCR Assay Development: Reaction condition optimization via clustering metrics.
• Equipment Maintenance: Early detection of droplet/chip generator wear.

— WHY IS THIS NEEDED?
Classic Westgard rules do not account for unique ddPCR physics.
Correct concentration can be obtained with poor partitioning, but result will be unreliable.
Specialized partition monitoring ensures true confidence in absolute quantification data.

⚠️ CRITICAL:
• Partition Count: <10,000 droplets significantly reduces dynamic range and precision.
• Cluster Separation: <500 amplitude units makes gating subjective and irreproducible.
• Rain: >5% requires review of amplification conditions or reagent replacement.
• Trend: Monotonic partition count decline over 5+ runs = preventive generator maintenance.

Key features:
• Five ddPCR-specific quality metrics
• Partition count trend analysis
• Integrated clustering and quantification assessment
• Automatic status classification
• Compliance with MIQE-dPCR guidelines

Critical parameters:
• Total Partitions: ≥ 10,000
• Positive Fraction: Within ±20% of expected
• Cluster Separation: > 500 amplitude units
• Rain Fraction: ≤ 5%
• Concentration Accuracy: Within ±25% of target

💡 Usage tips:
1. Baseline: Establish ExpectedPositiveFraction from first 10 runs of new control lot.
2. Gating: Use automatic gating to eliminate subjectivity in separation/rain assessment.
3. Oil/Reagents: Upon metric degradation, check droplet oil and master mix freshness.
4. Prevention: Replace droplet generator upon sustained partition count decline trend.
5. Documentation: Save 2D plots of controls together with JSON report.

⚠️ Note: This utility is a ddPCR-specific QC tool. It complements but does not replace standard Westgard concentration monitoring. Both approaches should be used together for complete ddPCR quality control.

input.csv

ControlLot,TargetName,RunDate,TotalPartitions,MinTotalPartitions,PositiveFraction,ExpectedPositiveFraction,PosClusterAmplitude,MinPosAmplitude,NegClusterAmplitude,MaxNegAmplitude,RainFraction,MaxRainFraction,MeasuredConcentration_copies_uL,TargetConcentration_copies_uL,ConcentrationTolerance_Percent
DDPCR-QC-LOT-A,RNase_P,2026-06-01,18500,10000,0.14,0.15,5200,3000,180,500,0.02,0.05,48.5,50.0,25
DDPCR-QC-LOT-A,RNase_P,2026-06-08,17800,10000,0.15,0.15,5100,3000,190,500,0.03,0.05,50.2,50.0,25
DDPCR-QC-LOT-A,RNase_P,2026-06-15,7200,10000,0.28,0.15,2800,3000,650,500,0.12,0.05,62.0,50.0,25
DDPCR-QC-LOT-B,EGFR_L858R,2026-06-01,20100,10000,0.08,0.08,4800,3000,150,500,0.01,0.05,12.3,12.5,25

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface and behaviour of ControlPartitionTrendChecker for Control Partition Trend Checker.

Domain limits URS input.csv FS IQ/OQ/PQ

Domain limits and critical parameters

Key fragments from the source description are shown below. Before production use, limits must be verified against the approved specification, registration dossier and local SOPs.

⚠️ CRITICAL:
• Partition Count: <10,000 droplets significantly reduces dynamic range and precision.
• Cluster Separation: <500 amplitude units makes gating subjective and irreproducible.
• Rain: >5% requires review of amplification conditions or reagent replacement.
Critical parameters:
• Total Partitions: ≥ 10,000
• Cluster Separation: > 500 amplitude units
• Rain Fraction: ≤ 5%

URS — User Requirements Specification

ID	Requirement	Criticality	Acceptance criterion
URS-001	The utility shall accept an input.csv file for Control Partition Trend Checker with headers defined in the data contract.	High	The file is processed without manual header editing.
URS-002	The utility shall perform deterministic QC evaluation without machine learning and without probabilistic conformance decisions.	High	Identical input data, rule version and configuration produce reproducible results.
URS-003	The utility shall validate mandatory fields, data types, ranges, units and domain plausibility.	High	Schema, conversion and range errors are explicitly reported.
URS-004	The utility shall apply domain limits and rules from the description, approved specification, registration dossier and local SOPs.	High	Each check has PASS/WARNING/FAIL and a clear message.
URS-005	The utility shall generate output.json with machine-readable results, source values, warnings, failures and critical findings.	High	JSON is suitable for LIMS/ELN/MES integration and QA/QC review.
URS-006	The utility shall preserve traceability between batch/sample, input file, applied rules and final status.	High	Output contains identifiers, checked parameters and audit metadata.
URS-007	The documentation shall support IQ/OQ/PQ, CSV/CSA and review by internal QA or inspectors.	Medium	URS, FS, input/output contract and test scenarios are supplied with the utility.
URS-008	The utility shall be used as a QC decision-support tool and not as a substitute for approved specifications and QA/QP release decision.	Medium	Documentation states change control and limit-verification expectations.

input.csv contract

#	Field	Type	Sample	Purpose
1	`ControlLot`	string / controlled vocabulary	`DDPCR-QC-LOT-A`	Batch or lot identifier used for traceability.
2	`TargetName`	string / controlled vocabulary	`RNase_P`	Controlled input parameter for deterministic QC rules.
3	`RunDate`	string / controlled vocabulary	`2026-06-01`	Controlled input parameter for deterministic QC rules.
4	`TotalPartitions`	decimal	`18500`	Controlled input parameter for deterministic QC rules.
5	`MinTotalPartitions`	decimal	`10000`	Controlled input parameter for deterministic QC rules.
6	`PositiveFraction`	integer / decimal	`0.14`	Controlled input parameter for deterministic QC rules.
7	`ExpectedPositiveFraction`	integer / decimal	`0.15`	Controlled input parameter for deterministic QC rules.
8	`PosClusterAmplitude`	decimal	`5200`	Controlled input parameter for deterministic QC rules.
9	`MinPosAmplitude`	decimal	`3000`	Controlled input parameter for deterministic QC rules.
10	`NegClusterAmplitude`	decimal	`180`	Controlled input parameter for deterministic QC rules.
11	`MaxNegAmplitude`	decimal	`500`	Controlled input parameter for deterministic QC rules.
12	`RainFraction`	integer / decimal	`0.02`	Controlled input parameter for deterministic QC rules.
13	`MaxRainFraction`	integer / decimal	`0.05`	Controlled input parameter for deterministic QC rules.
14	`MeasuredConcentration_copies_uL`	decimal	`48.5`	Component ratio; structural or formulation CQA.
15	`TargetConcentration_copies_uL`	decimal	`50.0`	Component ratio; structural or formulation CQA.
16	`ConcentrationTolerance_Percent`	decimal	`25`	Component ratio; structural or formulation CQA.

ControlLot,TargetName,RunDate,TotalPartitions,MinTotalPartitions,PositiveFraction,ExpectedPositiveFraction,PosClusterAmplitude,MinPosAmplitude,NegClusterAmplitude,MaxNegAmplitude,RainFraction,MaxRainFraction,MeasuredConcentration_copies_uL,TargetConcentration_copies_uL,ConcentrationTolerance_Percent
DDPCR-QC-LOT-A,RNase_P,2026-06-01,18500,10000,0.14,0.15,5200,3000,180,500,0.02,0.05,48.5,50.0,25
DDPCR-QC-LOT-A,RNase_P,2026-06-08,17800,10000,0.15,0.15,5100,3000,190,500,0.03,0.05,50.2,50.0,25
DDPCR-QC-LOT-A,RNase_P,2026-06-15,7200,10000,0.28,0.15,2800,3000,650,500,0.12,0.05,62.0,50.0,25

Input validation rules

ID	Field	Rule	Criticality
VR-001	`ControlLot`	The field shall match an approved dictionary or accepted string representation.	High
VR-002	`TargetName`	The field shall match an approved dictionary or accepted string representation.	High
VR-003	`RunDate`	The field shall match an approved dictionary or accepted string representation.	High
VR-004	`TotalPartitions`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-005	`MinTotalPartitions`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-006	`PositiveFraction`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-007	`ExpectedPositiveFraction`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-008	`PosClusterAmplitude`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-009	`MinPosAmplitude`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-010	`NegClusterAmplitude`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-011	`MaxNegAmplitude`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-012	`RainFraction`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-013	`MaxRainFraction`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-014	`MeasuredConcentration_copies_uL`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-015	`TargetConcentration_copies_uL`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-016	`ConcentrationTolerance_Percent`	The field shall match an approved dictionary or accepted string representation.	Medium

FS — Functional Specification

ID	Function	Implementation
FS-001	CLI execution	Support execution modes: demo mode without arguments and production mode input.csv output.json.
FS-002	CSV import	Read input.csv in UTF-8/CSV-compatible format and validate header and expected columns.
FS-003	Schema validation	Check mandatory fields, column count, unknown key fields and empty mandatory values.
FS-004	Type conversion	Convert numeric, flag and text values; invalid format is recorded as a row-level error.
FS-005	Domain rule engine	Apply rules for Control Partition Trend Checker, including critical limits from the description and approved specification.
FS-006	Status aggregation	Produce final status: FAIL for critical failure, WARNING for non-critical deviation, PASS for conformance.
FS-007	JSON export	Write output.json with detailed checks, source values, warnings, failures and critical findings.
FS-008	Audit support	Keep result structure suitable for review, deviation investigation and calculation reproduction.
FS-009	Integration contract	Support the scenario LIMS/ELN/MES → input.csv → utility → output.json → portal/admin review.
FS-010	Error handling	Return explicit messages for missing file, empty CSV, invalid schema, output write failure and invalid format.

Example output.json

{
  "utilityId": "controlpartitiontrendchecker",
  "utilityFolder": "ControlPartitionTrendChecker",
  "package": "LiquidBiopsy",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "processedAtUtc": "2026-06-10T00:00:00Z",
  "checks": [
    {
      "parameter": "ControlLot",
      "value": "DDPCR-QC-LOT-A",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-001"
    },
    {
      "parameter": "TargetName",
      "value": "RNase_P",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-002"
    },
    {
      "parameter": "RunDate",
      "value": "2026-06-01",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-003"
    },
    {
      "parameter": "TotalPartitions",
      "value": "18500",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-004"
    },
    {
      "parameter": "MinTotalPartitions",
      "value": "10000",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-005"
    },
    {
      "parameter": "PositiveFraction",
      "value": "0.14",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-006"
    },
    {
      "parameter": "ExpectedPositiveFraction",
      "value": "0.15",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-007"
    },
    {
      "parameter": "PosClusterAmplitude",
      "value": "5200",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-008"
    },
    {
      "parameter": "MinPosAmplitude",
      "value": "3000",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-009"
    },
    {
      "parameter": "NegClusterAmplitude",
      "value": "180",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-010"
    },
    {
      "parameter": "MaxNegAmplitude",
      "value": "500",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-011"
    },
    {
      "parameter": "RainFraction",
      "value": "0.02",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-012"
    }
  ],
  "criticalFindings": [],
  "warnings": [],
  "audit": {
    "inputHash": "sha256:<calculated at runtime>",
    "rulesVersion": "<utility executable version>",
    "documentation": "ControlPartitionTrendChecker.documentation.html"
  }
}

Traceability matrix

URS	FS	Test	Evidence
URS-001	FS-001, FS-002	OQ-001	Verify execution and import of valid input.csv.
URS-002	FS-005, FS-006	OQ-004	Repeat the same dataset and compare output.json.
URS-003	FS-003, FS-004, FS-010	OQ-002, OQ-003	Verify missing columns and invalid types.
URS-004	FS-005, FS-006	OQ-004, PQ-001	Verify critical deviations on real/boundary data.
URS-005	FS-007, FS-009	OQ-005	Verify JSON schema and downstream-system suitability.
URS-006	FS-008	OQ-006	Verify identifiers and audit metadata.
URS-007	FS-008, FS-010	IQ-001, OQ-007	Verify documentation completeness and control evidence.
URS-008	FS-005, FS-008	PQ-002	Verify review workflow and no replacement of QA decision.

IQ/OQ/PQ test scenarios

ID	Scenario	Expected result
IQ-001	Verify executable, input.csv, documentation and checksum availability.	Delivery set is complete; version is recorded.
OQ-001	Valid sample row from input.csv.	PASS or acceptable WARNING according to rules.
OQ-002	Remove a mandatory CSV column.	Schema error or FAIL with missing-column reference.
OQ-003	Place a non-numeric value into a numeric field.	Type-conversion error with row/field reference.
OQ-004	Set a critical parameter outside the limit.	FAIL and critical finding.
OQ-005	Verify output.json structure.	All mandatory sections are present and JSON is valid.
OQ-006	Verify batch/sample traceability.	Input and result identifiers match.
PQ-001	Verify 3–5 real user batches/samples.	Result is confirmed by QC/QA review.
PQ-002	Verify deviation workflow and manual QA decision.	Utility supports review but does not replace approved decision.

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.

Included in packages

Liquid Biopsy QC Suite

QC and pre-analytical control package for liquid biopsy workflows: cfDNA/ctDNA, CTC, EV/exosomes, methylation, NGS/qPCR/ddPCR, sample quality, contamination, sensitivity and reporting checks.

Open