TCID50InfectiousTiterCalculator

TCID50 Infectious Titer Calculator

Vet veterinary veterinary vaccines animal health adjuvants aquaculture batch release CSV→JSON

Utility description: TCID50 Infectious Titer Calculator

TCID50 Infectious Titer Calculator — Infectious Titer Calculator (Spearman-Kärber)

ℹ️ Utility calculates viral infectious titer (TCID50) using the Spearman-Kärber method, which is the standard for virological studies and vaccine quality control:
• Input Data: Series of decimal dilutions and number of positive wells (with CPE) at each dilution.
• Algorithm: Spearman-Kärber formula.
• Result: Titer in log10 TCID50/mL and absolute value.
• Validation: Check for presence of 100% positive wells for calculation accuracy.

⚠️ IMPORTANT:
• Method requires that dilution series starts with concentration giving 100% positive result and ends with 0%.
• If no 100% positive wells are present, calculation may be inaccurate or impossible.
• Inoculum volume is critical for conversion to per mL.

Usage:
TCID50InfectiousTiterCalculator.exe → demo mode (console output)
TCID50InfectiousTiterCalculator.exe input.csv output.json → evaluate your data

Input format:
BatchNumber,ProductName,DilutionSeries,PositiveWells,ReplicatesPerDilution,InoculumVolume_ml,MinRequiredTiter_Log10

Example:
TCID-001,Vaccine,"-3,-4,-5,-6,-7","8,8,5,1,0",8,0.1,6.0

— WHY IS THIS NEEDED?
TCID50 (Tissue Culture Infectious Dose 50%) is the amount of virus required to infect 50% of cell cultures.
It is the main method for standardization of live viral vaccines and determination of virus activity in research.
Automation of calculation eliminates arithmetic errors common in manual counting.

⚠️ CRITICAL:
• CPE (Cytopathic Effect): Must be clearly identified by operator or image analysis system.
• Controls: Positive and negative controls are mandatory for test validation.
• Statistics: Spearman-Kärber method provides unbiased estimate of titer if experimental design conditions are met.

Key features:
• Automatic calculation by Spearman-Kärber formula
• Inoculum volume consideration
• Dilution series validity check
• Generation of reports for virology labs and LIMS LabWare
• Compliance with Ph. Eur. 5.2.14 requirements

Critical parameters:
• Presence of 100% positive wells
• Correct dilution step (usually 1 log10)
• Accurate inoculum volume account

💡 Usage tips:
1. Plate Design: Use at least 4-8 replicates per dilution to increase accuracy.
2. Range: Select dilutions to cover the transition from 100% to 0% positive wells.
3. Blinding: CPE assessment should be done "blind" to exclude bias.
4. Interpretation: TCID50 is not equal to PFU (Plaque Forming Units). Usually 1 TCID50 ≈ 0.69 PFU, but it depends on the system.

⚠️ Note: Unlike Plaque Assay, TCID50 does not require visualization of individual plaques and is suitable for viruses that do not form clear plaques.

input.csv

BatchNumber,ProductName,DilutionSeries,PositiveWells,ReplicatesPerDilution,InoculumVolume_ml,MinRequiredTiter_Log10
TCID-2026-VAC-001,Live Attenuated Virus,"-3,-4,-5,-6,-7","8,8,5,1,0",8,0.1,6.0
TCID-2026-VAC-002,Another Strain,"-2,-3,-4,-5","4,4,2,0",4,0.05,5.0
TCID-2026-LOW-003,Low Titer Sample,"-1,-2,-3","1,0,0",8,0.1,6.0

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface and behaviour of TCID50InfectiousTiterCalculator for TCID50 Infectious Titer Calculator.

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.

ℹ️ Utility calculates viral infectious titer (TCID50) using the Spearman-Kärber method, which is the standard for virological studies and vaccine quality control:
• Inoculum volume is critical for conversion to per mL.
⚠️ CRITICAL:
• CPE (Cytopathic Effect): Must be clearly identified by operator or image analysis system.
• Compliance with Ph. Eur. 5.2.14 requirements
Critical parameters:

URS — User Requirements Specification

ID	Requirement	Criticality	Acceptance criterion
URS-001	The utility shall accept an input.csv file for TCID50 Infectious Titer Calculator 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	`BatchNumber`	string / controlled vocabulary	`TCID-2026-VAC-001`	Batch or lot identifier used for traceability.
2	`ProductName`	string / controlled vocabulary	`Live Attenuated Virus`	Product or dosage-form name under evaluation.
3	`DilutionSeries`	string / controlled vocabulary	`-3,-4,-5,-6,-7`	Controlled input parameter for deterministic QC rules.
4	`PositiveWells`	string / controlled vocabulary	`8,8,5,1,0`	Controlled input parameter for deterministic QC rules.
5	`ReplicatesPerDilution`	integer / decimal	`8`	Controlled input parameter for deterministic QC rules.
6	`InoculumVolume_ml`	decimal	`0.1`	Volume/dose used for load, limit or release calculation.
7	`MinRequiredTiter_Log10`	decimal	`6.0`	Controlled input parameter for deterministic QC rules.

BatchNumber,ProductName,DilutionSeries,PositiveWells,ReplicatesPerDilution,InoculumVolume_ml,MinRequiredTiter_Log10
TCID-2026-VAC-001,Live Attenuated Virus,-3,-4,-5,-6,-7,8,8,5,1,0,8,0.1,6.0
TCID-2026-VAC-002,Another Strain,-2,-3,-4,-5,4,4,2,0,4,0.05,5.0
TCID-2026-LOW-003,Low Titer Sample,-1,-2,-3,1,0,0,8,0.1,6.0

Input validation rules

ID	Field	Rule	Criticality
VR-001	`BatchNumber`	The field shall match an approved dictionary or accepted string representation.	High
VR-002	`ProductName`	The field shall match an approved dictionary or accepted string representation.	High
VR-003	`DilutionSeries`	The field shall match an approved dictionary or accepted string representation.	High
VR-004	`PositiveWells`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-005	`ReplicatesPerDilution`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-006	`InoculumVolume_ml`	The field shall match an approved dictionary or accepted string representation.	Medium
VR-007	`MinRequiredTiter_Log10`	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 TCID50 Infectious Titer Calculator, 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": "tcid50infectioustitercalculator",
  "utilityFolder": "TCID50InfectiousTiterCalculator",
  "package": "Vet",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "processedAtUtc": "2026-06-10T00:00:00Z",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "TCID-2026-VAC-001",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-001"
    },
    {
      "parameter": "ProductName",
      "value": "Live Attenuated Virus",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-002"
    },
    {
      "parameter": "DilutionSeries",
      "value": "-3,-4,-5,-6,-7",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-003"
    },
    {
      "parameter": "PositiveWells",
      "value": "8,8,5,1,0",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-004"
    },
    {
      "parameter": "ReplicatesPerDilution",
      "value": "8",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-005"
    },
    {
      "parameter": "InoculumVolume_ml",
      "value": "0.1",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-006"
    },
    {
      "parameter": "MinRequiredTiter_Log10",
      "value": "6.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Deterministic rule-based check result",
      "ruleReference": "FS-RULE-007"
    }
  ],
  "criticalFindings": [],
  "warnings": [],
  "audit": {
    "inputHash": "sha256:<calculated at runtime>",
    "rulesVersion": "<utility executable version>",
    "documentation": "TCID50InfectiousTiterCalculator.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

Infectious Diseases QC Suite

QC utility package for infectious diseases: antibacterial, antiviral, antifungal and antiparasitic products, microbiology, sterility, endotoxins, viral safety and vaccine release checks.

Open

Vet — Veterinary QC Utilities

Vet is designed for veterinary pharmaceuticals and vaccines: adjuvants, antigens, autogenous vaccines, aquaculture, feed/premixes, antimicrobial and antiparasitic products, sterility and batch release.

Open