Sample Collection Card Dyes Stable Under EtO and UV Exposure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current indicator dyes used in forensic sample collection cards fade on exposure to EtO and UV radiation, compromising the stability and integrity of DNA analysis.
Innovation Solution
Use of alternative dyes such as Alizarin Red, Methylene Blue, Reactive Blue 4, Alcian Blue, Indigo Carmine, and Bromophenol Blue, which exhibit resistance to EtO and UV, maintain constant color intensity, and are water-soluble, ensuring compatibility with manufacturing and analysis processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If current indicator dyes (Chlorophenol Red, Indigo Carmine, Methylene Blue) are used in sample collection cards, then the dyes provide visible color indication for sample location, but the dyes fade on exposure to EtO and UV radiation, compromising stability
Solution Approach 1:
The patent changes the chemical parameters of the dye molecules by selecting specific dyes (Cresol Red, Bromothymol Blue, Phenol Red, Neutral Red, Methyl Red) that have inherent resistance to EtO and UV degradation. These dyes maintain their color properties under sterilization conditions while still providing visible indication, thus resolving the contradiction between visibility and stability.
2Ease of operation
If dyes are used to indicate sample location, then sample collection is visually identifiable, but the dyes may interfere with or inhibit DNA analysis and PCR reactions
Solution Approach 1:
The patent employs dyes that are present in minimal concentrations and are washed away or degraded during the DNA extraction and analysis process. The dyes serve their indicating function during collection but do not persist to interfere with subsequent molecular biology operations, effectively making them disposable indicators that complete their purpose and disappear before causing harm.
Solution Approach 2:
The patent uses dyes as intermediary substances that provide visual information during sample collection but do not directly interact with DNA or PCR reagents. The dyes act as temporary mediators for sample location identification, separated from the critical DNA analysis steps through washing or degradation, thus preventing harmful interactions.
3Ease of manufacture
If dyes are applied to solid support for sample collection, then sample location is indicated, but the dyes must be water-soluble for manufacturing compatibility while maintaining color stability
Solution Approach 1:
The patent selects dyes with specific chemical parameters that simultaneously provide water solubility for manufacturing compatibility and resistance to EtO/UV degradation. Dyes like Cresol Red, Bromothymol Blue, and Phenol Red have molecular structures that allow them to be dissolved in water-based manufacturing processes while maintaining color stability under sterilization conditions, resolving the contradiction between manufacturability and stability.
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
These dyes provide stable and even color indication, preventing interference with DNA analysis and maintaining the integrity of forensic sample workflows like STR profiling.
Implementation Method 1
This is classified as a pH dye that changes colour from purple to yellow/white on application of an aqueous biological sample
Implementation Method 2
The dye also indicates sample location via a chromatographic method in which the sample physically moves the dye in a solvent front generating a paler white area that co-localises with the sample
Implementation Method 3
EtO facilitates the production of un-amplifiable DNA by crosslinking functional groups located in the DNA molecule to solid support surfaces thereby making them inaccessible to DNA polymerases used during PCR
Data Source
AI summary
The present invention relates to means for collection of biological samples. Specifically, the present invention provides a solid support for collection, storage and subsequent analysis of a biological sample as well as methods for use of the solid support of the invention and a kit comprising the solid support of the invention.