Microorganism Detection Using Multi-Color Redox Indicators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The Most Probable Number (MPN) method for detecting microorganisms is limited by its inability to accurately distinguish between different degrees of microbial growth and its discontinuous nature, leading to reduced accuracy in determining the relative content of microorganisms in samples.
Innovation Solution
Incorporating a redox indicator with a color change range of three or more easily recognizable colors into the medium, allowing for multiple readings during and after culture, and using a formula to calculate the relative content based on color or absorbance changes, thereby enhancing the method's precision and comparability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the conventional MPN method is used to detect microorganism content, then the detection process is simple and easy to operate, but the measurement precision and accuracy are reduced due to inability to distinguish different degrees of microbial growth
Solution Approach 1:
The patent applies color change indicators (redox indicators) to the culture medium that exhibit three or more easily distinguishable color changes corresponding to different degrees of microbial growth. This allows the detection system to differentiate between low, medium, and high levels of microorganism activity, thereby improving measurement precision without requiring complex instrumentation. The color changes provide visual feedback that enhances the accuracy of microorganism content determination while maintaining operational simplicity.
Solution Approach 2:
The patent replaces the conventional binary (positive/negative) reading system with a multi-level optical detection system based on color intensity and hue variations. By using redox indicators that produce distinct color changes, the method substitutes simple visual or spectrophotometric measurement for complex mechanical counting or analysis, thereby improving measurement precision while keeping the system relatively simple.
2Measurement precision
If the conventional MPN method records only positive or negative culture results, then the operation is simple, but the data continuity and comparability between samples are reduced
Solution Approach 1:
The patent introduces redox indicators that produce three or more distinct color changes in the culture medium, each corresponding to different levels of microbial growth. This allows operators to record nuanced results (e.g., light color change, moderate color change, intense color change) rather than simple positive/negative outcomes. The enhanced color differentiation improves data continuity and comparability across samples while maintaining ease of operation through visual assessment.
Solution Approach 2:
The patent uses redox indicators as intermediary substances that translate microbial metabolic activity into graduated color changes. These indicators act as mediators between the microorganisms and the observer, providing continuous visual information about growth levels. This intermediary system enables more detailed and comparable data recording without significantly complicating the operational process.
3Measurement precision
If a single reading is taken at the end of culture in the conventional MPN method, then the process is quick and simple, but the accuracy is reduced because it cannot capture the degree of positivity
Solution Approach 1:
The patent employs redox indicators that produce distinct color changes at different stages of microbial growth, allowing a single reading to capture the degree of positivity. The graduated color scale (three or more distinguishable colors) enables the observer to determine not just whether growth occurred, but also the extent of growth, thereby improving accuracy without requiring multiple time-point readings.
Solution Approach 2:
The patent uses redox indicators that are pre-added to the culture medium before inoculation. These indicators are already in position to detect and signal microbial growth as it occurs, eliminating the need for additional sampling or reading steps at intermediate time points. The preliminary placement of the detection system allows accurate single-reading assessment.
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
The method provides more precise and accurate determination of microorganism content, with improved data continuity and comparability between samples, and better correlation with microscopic counting results.
Implementation Method 1
adding a redox indicator to a medium to obtain an indicator medium; the color change range of the redox indicator includes three or more than three colors that can be easily recognized by a naked eye
Data Source
AI summary
Provided is a method for detecting and counting the relative content of a microorganism, comprising: adding a redox indicator to a growth medium to produce an indicating growth medium; the range of color variation of the redox indicator comprising three or more colors that can be easily recognized by the naked eye; diluting a sample to be tested, configuring multiple degrees of dilution, configuring multiple parallels for each degree of dilution, and growing the diluted test sample using the indicating growing medium; reading the color or absorbance of the indicating growth medium while growing and/or when growing is completed; and producing the relative content of a microorganism in the test sample on the basis of the level of color variation or the value of absorbance variation of the indicating growth medium.