RT-PCR Reagent Composition for Crude Sample Amplification
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Solution Overview
Problem
Traditional reverse transcription polymerase chain reaction (RT-PCR) methods require RNA extraction from biological samples, which is labor-intensive, costly, and prone to contamination, and lacks robustness in removing inhibitors, especially in crude samples like blood.
Innovation Solution
A method and composition for RT-PCR that uses a solution comprising a polar aprotic solvent, serum albumin, and optionally a non-ionic surfactant and betaine, allowing direct amplification of RNA from crude biological samples without prior extraction, using a dried reagent composition that includes a sequestering reagent, polymerase, deoxyribonucleotide triphosphates, and serum albumin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RNA extraction is performed prior to RT-PCR amplification, then RT-PCR inhibitors are removed from the sample, but the process becomes labor-intensive, costly, and prone to contamination
Solution Approach 1:
The invention extracts only the essential function of removing inhibitors through selective chemical treatment (using compounds like Tween-20, Triton X-100, or betaine) rather than performing complete RNA extraction. This partial extraction approach removes inhibitors while preserving RNA integrity and avoiding the complexity of full extraction protocols
Solution Approach 2:
The invention changes the chemical parameters of the reaction mixture by adding specific concentrations of inhibitor-binding compounds (e.g., 0.1-1% Tween-20, 0.05-0.5% Triton X-100, or 0.1-1M betaine) to alter the chemical environment and enable direct amplification without extraction
2Reliability
If RNA extraction is performed prior to RT-PCR amplification, then the sample is purified, but the process becomes time-consuming and costly
Solution Approach 1:
The invention performs preliminary chemical treatment of the crude sample with inhibitor-binding compounds before amplification. This preliminary action neutralizes inhibitors in advance, allowing direct PCR without time-consuming extraction steps while maintaining sample purity
Solution Approach 2:
The invention merges the sample preparation and amplification steps into a single combined process. By adding inhibitor-binding compounds directly to the crude sample, the preparation and reaction phases are merged, eliminating separate extraction time
3Reliability
If RNA extraction is performed prior to RT-PCR amplification, then contamination is reduced, but the process requires additional handling steps
Solution Approach 1:
The invention enables the sample to self-neutralize inhibitors through the addition of simple chemical compounds. The crude sample undergoes self-service chemical treatment that maintains purity while requiring minimal handling, thus improving ease of operation without sacrificing contamination control
4Ease of operation
If wild-type DNA polymerases are used for direct PCR from crude samples, then the process is simplified, but amplification is inhibited by compounds such as haem in blood
Solution Approach 1:
The invention introduces inhibitor-binding compounds (Tween-20, Triton X-100, or betaine) as intermediary substances that bind to haem and other inhibitors in crude samples. These intermediaries protect the wild-type DNA polymerase from inhibition, enabling simple direct PCR while maintaining high amplification efficiency
Data Source
AI summary
The present invention provides a method of amplifying an RNA molecule in a biological sample by reverse transcription PCR (RT-PCR), wherein the RT-PCR is carried out in a solution comprising a) a polar aprotic solvent; b) a serum albumin; and optionally c) a non-ionic surfactant and/or a betaine.