Spectrophotometer Suitability Using Blue Dye Standards

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Solution Overview

Problem

Existing methods for determining protein concentration using spectrophotometers are inconsistent and lack standardized system suitability criteria, leading to variability in measurement accuracy.

Innovation Solution

A method involving the use of Patent Blue dye (PBD) or AMG Blue dye at multiple wavelengths (280 nm, 310 nm, 412 nm, and 510 nm or 615 nm) to assess the suitability of variable and fixed path length spectrophotometers, with absorbance readings within 10% or 5% of the certificate of analysis and a relative standard deviation (RSD) of ≤ 5% as criteria for suitability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If spectrophotometers are used to determine protein concentration without standardized system suitability criteria, then measurement can be performed quickly, but measurement precision and reliability deteriorate due to inconsistency and variability

Engineering Contradiction:
Improveprotein concentration measurement accuracyVSAvoidsystem suitability assessment procedure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements preliminary system suitability testing using blue dye standards before actual protein concentration measurements. This preliminary action establishes instrument performance criteria (absorbance readings within 10% or 5% of certificate of analysis, RSD ≤ 5%) to ensure subsequent measurements will be reliable, resolving the contradiction by preparing the measurement system in advance rather than dealing with inconsistencies during actual measurement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the measurement parameter from direct protein concentration determination to blue dye absorbance measurement at multiple wavelengths (280 nm, 310 nm, 412 nm, 510 nm, or 615 nm). This parameter substitution allows indirect assessment of instrument suitability through well-established dye standards, improving measurement precision without requiring complex direct protein reference materials.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If multiple wavelengths are measured to assess instrument suitability, then measurement precision improves through more comprehensive evaluation, but loss of time increases due to multiple measurements

Engineering Contradiction:
Improveinstrument suitability assessment accuracyVSAvoidtime for absorbance measurements
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by selecting specific critical wavelengths (280 nm and 310 nm primarily, with optional 412 nm, 510 nm, or 615 nm) rather than measuring across the entire spectrum. This partial measurement approach provides sufficient instrument suitability assessment without the excessive time investment of comprehensive multi-wavelength scanning, resolving the contradiction between thoroughness and efficiency.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent performs wavelength selection and system suitability assessment as preliminary actions before actual protein measurements. By pre-establishing which wavelengths are necessary for instrument characterization and pre-validating instrument performance at these wavelengths, the time cost of multiple wavelength measurements is incurred once during setup rather than repeatedly during sample analysis.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If strict system suitability criteria (≤5% RSD, within 5-10% of certificate values) are enforced, then reliability of protein concentration determination improves, but productivity decreases due to additional validation steps

Engineering Contradiction:
Improveprotein concentration determination reliabilityVSAvoidthroughput of protein concentration measurements
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent enforces strict system suitability criteria (RSD ≤ 5%, absorbance within 10% or 5% of certificate of analysis) as preliminary validation steps before protein concentration measurements. By ensuring instrument reliability in advance through blue dye standard measurements, the actual protein analysis throughput is protected from rejections due to instrument drift, making the productivity loss during validation worthwhile for maintaining overall measurement reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback through system suitability testing that monitors instrument performance continuously. When blue dye absorbance readings fall outside acceptance criteria, the system provides feedback that protein measurements should not be performed until instrument performance is restored. This feedback loop ensures reliability without permanently reducing productivity, as measurements can proceed continuously once validation is established.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Ensures consistent and accurate protein concentration measurements by establishing precise system suitability criteria, enhancing the reliability and precision of protein concentration determination in therapeutic proteins.

Implementation Method 1

measuring the absorbance of Patent Blue dye (PBD) or AMG Blue Dye (ABD) at least two wavelengths, the first wavelength of 280 nm and the subsequent wavelength(s) selected from the group consisting of 310 nm, 412 nm, 510 nm and 615 nm

Methodology Applied
Scientific EffectAbsorbance spectroscopy: Absorption Spectroscopy

Data Source

PatentEP3894839B1System suitability method for use with protein concentration determination by slope
Publication Date: 2026.01.28 AMGEN INC
  • EP3894839B1 patent drawingFigure 1
  • EP3894839B1 patent drawingFigure 2
  • EP3894839B1 patent drawingFigure 3

AI summary

Disclosed are methods of determining the suitability of a variable-length spectrophotometer using Patent Blue dye or AMG Blue dye. Also disclosed herein are methods of determining the suitability of a fixed path length spectrophotometer for determining protein concentration of a protein sample. AMG Blue dye may also be used to determine the suitability of fixed path length spectrophotometers.