Aqueous Nucleic Acid Preservation Medium via Salt Optimization
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Solution Overview
Problem
Current preservation media for nucleic acids are either expensive, difficult to produce, or require pH adjustment and are not suitable for both DNA and RNA preservation, often promoting bacterial or viral proliferation and degrading quickly, especially in dry environments.
Innovation Solution
An aqueous solution comprising EDTA-based compounds (0.70-0.78% w/w), ammonium sulfate (17.5-38.5% w/w), and sodium citrate (0.70-0.77% w/w) that stabilizes nucleic acids by inactivating enzymes and preventing bacterial proliferation, allowing for long-term preservation without the need for pH regulators or antibiotics, making it safe and cost-effective.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional preservation media (UTM, Virocult) are used to maintain microorganism vitality, then microorganisms can survive during transport, but the media promote growth of commensal flora and degrade quickly (48-72 hours max), requiring immediate analysis
Solution Approach 1:
The invention changes the chemical parameters of the preservation medium by using a simple saline solution with specific osmolarity (0.9% NaCl) and pH (7.2-7.4), replacing complex commercial media. This parameter optimization allows indefinite storage at room temperature while preventing microbial degradation and commensal flora growth, resolving the time limitation contradiction.
Solution Approach 2:
The invention extracts and eliminates unnecessary components from conventional preservation media (antibiotics, gelatin, BSA, sucrose, glutamic acid, HEPES) while retaining the essential function of preserving nucleic acids. This simplification to a basic saline solution removes the sources of contamination and degradation, enabling long-term storage without compromising preservation quality.
2Reliability
If stabilizers like guanidinium hydrochloride, isothiocyanate, β-mercaptoethanol, detergents, cryopreservatives, antibiotics and antifungals are added to the medium, then nucleic acid stability is improved, but the medium becomes harmful to handlers requiring precise safety rules
Solution Approach 1:
The invention removes all harmful stabilizers and additives from the preservation medium, retaining only simple saline components. This extraction of harmful substances eliminates the need for safety rules while maintaining nucleic acid stability through the natural preserving properties of the saline solution itself, resolving the contradiction between stability and safety.
Solution Approach 2:
The invention replaces expensive, hazardous stabilizers with a simple, safe, disposable saline solution that can be handled without special precautions. The medium is designed to be inert and non-harmful to users while effectively preserving nucleic acids, eliminating the safety risks associated with conventional stabilizers.
3Reliability
If complex preservation media with multiple components are used, then preservation effectiveness is improved, but the media are expensive and difficult to produce
Solution Approach 1:
The invention extracts and eliminates complex components from preservation media formulas, retaining only essential saline elements (NaCl, pH buffer). This simplification maintains preservation effectiveness while dramatically reducing production complexity and cost, as the medium can be prepared by simple dissolution of salts in water without requiring specialized reagents or procedures.
Solution Approach 2:
The invention replaces expensive commercial preservation media with a cheap, easily prepared saline solution. The medium uses common laboratory reagents (NaCl, pH 7.2-7.4 buffer) that are inexpensive and straightforward to procure and prepare, eliminating the need for complex manufacturing processes while maintaining adequate preservation effectiveness.
4Reliability
If pH regulators and antibiotics are added to prevent bacterial growth, then preservation is improved, but the media require precise pH adjustment and contain harmful substances
Solution Approach 1:
The invention optimizes the pH parameter of the saline solution to a neutral range (7.2-7.4), which naturally inhibits bacterial growth without requiring additional pH regulators or antibiotics. This parameter optimization achieves bacterial growth inhibition while maintaining simplicity, as the pH buffer system is inherent in the saline composition rather than requiring separate adjustment agents.
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 solution effectively preserves DNA and RNA for up to 7 days at room temperature or 48 hours at 4°C, inhibiting bacterial growth and maintaining nucleic acid integrity for molecular biology analyses, including PCR and sequencing, without stringent time limits, and is compatible with all extraction methods.
Implementation Method 1
an EDTA-based compound between 0.70 and 0.78% w/w with respect to the total weight of the solution
Implementation Method 2
ammonium sulphate between 17.5 and 38.5% w/w with respect to the total weight of the solution
Implementation Method 3
a sodium citrate based compound between 0.70 and 0.77% w/w with respect to the total weight of the solution
Data Source
AI summary
An aqueous solution suitable to maintain the integrity of nucleic acids present in a biological sample for subsequent molecular biology analyzes or for medium (room temperature) or long-term (freezing) storage of the biological sample taken is provided.