Pathogen Nucleic Acid Detection in Whole Blood
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Solution Overview
Problem
Current diagnostic assays for detecting pathogens in whole blood samples require extensive sample preparation, are time-consuming, and lack sensitivity, especially in the picomolar range, necessitating a rapid and sensitive detection method for point-of-care clinical decision making.
Innovation Solution
A method involving erythrocyte lysis of whole blood samples, followed by centrifugation, resuspension, and PCR amplification of target nucleic acids, which are then detected using magnetic particles and an RF coil in a device capable of detecting changes in magnetic resonance signals to identify pathogens like bacteria and fungi at concentrations as low as 10 cells/mL.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional diagnostic assays are used for pathogen detection in whole blood, then detection sensitivity can be achieved, but extensive sample preparation and time consumption are required
Solution Approach 1:
The patent applies preliminary action by performing erythrocyte lysis and nucleic acid extraction in advance as pre-processing steps before the actual detection. The whole blood sample undergoes red blood cell lysis to release intracellular pathogens, followed by nucleic acid extraction and concentration, so that when detection begins, the sample is already prepared and concentrated, eliminating the need for time-consuming preparation during the detection process itself.
Solution Approach 2:
The patent segments the detection process into distinct modular steps: (1) erythrocyte lysis to release pathogens from red blood cells, (2) nucleic acid extraction and concentration, (3) PCR amplification, and (4) detection. This segmentation allows each step to be optimized independently and enables parallel processing or automation, significantly reducing total preparation time while maintaining detection sensitivity.
2Measurement precision
If picomolar concentration paramagnetic particles are used for sensitive detection, then detection sensitivity improves, but binding events become rate-limiting due to low collision frequency
Solution Approach 1:
The patent performs preliminary concentration of pathogen nucleic acids from the whole blood sample before the detection step. By extracting and concentrating nucleic acids in advance, the effective concentration of target molecules is increased dramatically, ensuring that when paramagnetic particles are introduced, there are sufficient target molecules to bind to, eliminating the rate-limiting effect of low collision frequency while maintaining the sensitivity benefits of using low concentrations of paramagnetic particles.
3Measurement precision
If up-front sample preparation is performed for pathogen detection, then detection accuracy improves, but the overall testing time increases
Solution Approach 1:
The patent applies the skipping principle by using rapid erythrocyte lysis methodology that completes the critical sample preparation step in minutes rather than hours. The lysis buffer quickly disrupts red blood cell membranes to release intracellular pathogens, and the subsequent nucleic acid extraction and concentration steps are performed using optimized protocols that minimize processing time, allowing the assay to rush through the preparation phase without compromising detection accuracy.
Solution Approach 2:
The patent changes physical and chemical parameters to accelerate sample preparation while maintaining accuracy. This includes using specific lysis buffers with optimized pH and ionic strength for rapid cell disruption, adjusting temperature parameters for faster nucleic acid extraction, and modifying centrifugation speeds and durations to quickly separate components. These parameter optimizations reduce preparation time while preserving detection accuracy.
4Measurement precision
If single tests for individual analytes are performed, then detection specificity is maintained, but multiplex detection capability is lost
Solution Approach 1:
The patent implements universality by designing a single detection platform that can simultaneously detect multiple different pathogens and analytes. The system uses universal primers and probes that can bind to conserved regions across different pathogen genomes, allowing one assay to detect bacteria, fungi, and other pathogens in a single test. This multi-functional approach maintains detection specificity through pathogen-specific targeting while enabling multiplex capability to detect multiple analytes simultaneously.
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
Enables rapid, accurate detection of pathogens in whole blood with minimal sample preparation, achieving sensitivity in the picomolar range and facilitating point-of-care diagnostics.
Implementation Method 1
magnetic sensors cause changes in properties of neighboring water molecules (or any solvent molecule with free hydrogens) of a sample, which can be detected by magnetic resonance (NMR/MRI) techniques
Implementation Method 2
centrifuging the mixture of step (a) to form a supernatant and a pellet
Data Source
Figure 1A
Figure 1B
Figure 2~2E
AI summary
This invention features methods for amplifying and detecting a target pathogen nucleic acid in a whole blood sample.