Selective Lysis of Blood Cells for Bacterial DNA Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The detection of bacterial pathogens in blood samples is hindered by the abundance of human DNA and cellular components, which increases background noise and viscosity, making it challenging to detect low levels of bacterial DNA using PCR-based methods.
Innovation Solution
A method involving the selective lysis of white and red blood cells using a non-ionic detergent and alkaline buffer at a pH of 9.0, allowing bacteria and fungi to remain intact, thereby reducing human DNA interference and improving detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If large volumes of blood are used to detect minute amounts of bacteria, then detection sensitivity is improved, but the background noise from human DNA increases dramatically
Solution Approach 1:
The patent extracts and removes human DNA from the blood sample using selective lysis conditions (pH 9.0 buffer with non-ionic detergent) that lyse human cells while preserving bacterial cells. This extraction step eliminates the harmful background noise from human DNA before PCR analysis, enabling sensitive detection of minute bacterial amounts without the interference of abundant human genetic material.
2Ease of manufacture
If whole blood is used directly for PCR detection, then no further processing is needed, but the high amount of cellular material complicates pathogen detection
Solution Approach 1:
The patent performs preliminary selective lysis of human cells before the PCR detection step. By pre-treating the blood sample with pH 9.0 buffer and non-ionic detergent to lyse human cells and release their DNA, the subsequent PCR reaction is performed on a simplified sample matrix. This preliminary action removes the complicating cellular material while maintaining bacterial integrity for accurate pathogen detection.
3Measurement precision
If human cells are lysed to remove human DNA, then detection sensitivity is improved, but proteins and membranes from lysed cells increase sample viscosity
Solution Approach 1:
The patent utilizes specific parameter changes - particularly pH adjustment to 9.0 and the use of non-ionic detergents - to achieve selective lysis of human cells. These parameter changes create conditions where human cell membranes become permeable and rupture, releasing DNA while the subsequent neutralization step (returning pH to 7.0) stabilizes the lysate. This controlled parameter manipulation maximizes DNA release while minimizing viscosity-increasing byproducts.
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
This approach enhances the sensitivity of bacterial DNA detection by minimizing human DNA interference and maintaining the integrity of bacterial DNA, enabling the detection of minute bacterial amounts in blood samples without compromising RNA stability.
Implementation Method 1
A method involving the selective lysis of white and red blood cells using a non-ionic detergent and alkaline buffer at a pH of 9.0, allowing bacteria and fungi to remain intact
Data Source
AI summary
The present invention relates to methods for the specific lysis of eukaryotic cells in a sample containing microorganisms such as bacterium and fungus by incubating the sample in a buffer of around pH 9 that contains a non-ionic detergent.