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Acoustophoretic sample preparation for PCR in sepsis diagnostics

Punkkinen, Matleena LU (2013) EEM820 20122
Department of Biomedical Engineering
Abstract
Sepsis is a serious clinical syndrome and one of the most common causes of death. It is defined as a microbial invasion and excessive immune reaction. There is no common cure for sepsis, and mortality in sepsis is high and rises quickly, so it is important to start precise treatment quickly. Sepsis is, however, hard to diagnose, as it has no symptoms specific to it alone, and thus new ways to diagnose sepsis and its
cause are needed.
This study was part of an effort to develop a polymerase chain reaction (PCR)-based diagnostic system for detecting and identifying bacteria in blood in sepsis. The blood sample is first prepared by separating the substances that inhibit PCR in blood with acoustophoresis, using ultrasound to direct the... (More)
Sepsis is a serious clinical syndrome and one of the most common causes of death. It is defined as a microbial invasion and excessive immune reaction. There is no common cure for sepsis, and mortality in sepsis is high and rises quickly, so it is important to start precise treatment quickly. Sepsis is, however, hard to diagnose, as it has no symptoms specific to it alone, and thus new ways to diagnose sepsis and its
cause are needed.
This study was part of an effort to develop a polymerase chain reaction (PCR)-based diagnostic system for detecting and identifying bacteria in blood in sepsis. The blood sample is first prepared by separating the substances that inhibit PCR in blood with acoustophoresis, using ultrasound to direct the particles. This study aimed at determining how acoustophoresis and the presence of inhibiting agents or contamination in samples affected PCR and how effectively acoustophoresis had to clean a blood sample so that PCR could reliably detect bacteria in it.
Limit of detection for PCR was approximately 150 bacteria per sample due to high bacterial background. At approximately 0.003–0.03% blood plasma had very little effect on detection. PCR tolerated red blood cells up to approximately dilution 1:15000, but whole blood reduced amount of detected bacteria by 50% even at very high dilutions. Acoustophoresis could separate red blood cells and other from diluted blood efficiently, although detection of bacteria was somewhat affected. A large part of the bacteria were also lost during the acoustophoretic run. In spite of the problems, separation and detection of the bacteria seemed to work relatively well for
an unoptimized system. (Less)
Please use this url to cite or link to this publication:
author
Punkkinen, Matleena LU
supervisor
organization
course
EEM820 20122
year
type
H2 - Master's Degree (Two Years)
subject
language
English
additional info
2013-02
id
3626244
date added to LUP
2013-03-26 12:48:55
date last changed
2015-10-08 09:54:17
@misc{3626244,
  abstract     = {Sepsis is a serious clinical syndrome and one of the most common causes of death. It is defined as a microbial invasion and excessive immune reaction. There is no common cure for sepsis, and mortality in sepsis is high and rises quickly, so it is important to start precise treatment quickly. Sepsis is, however, hard to diagnose, as it has no symptoms specific to it alone, and thus new ways to diagnose sepsis and its
cause are needed.
This study was part of an effort to develop a polymerase chain reaction (PCR)-based diagnostic system for detecting and identifying bacteria in blood in sepsis. The blood sample is first prepared by separating the substances that inhibit PCR in blood with acoustophoresis, using ultrasound to direct the particles. This study aimed at determining how acoustophoresis and the presence of inhibiting agents or contamination in samples affected PCR and how effectively acoustophoresis had to clean a blood sample so that PCR could reliably detect bacteria in it.
Limit of detection for PCR was approximately 150 bacteria per sample due to high bacterial background. At approximately 0.003–0.03% blood plasma had very little effect on detection. PCR tolerated red blood cells up to approximately dilution 1:15000, but whole blood reduced amount of detected bacteria by 50% even at very high dilutions. Acoustophoresis could separate red blood cells and other from diluted blood efficiently, although detection of bacteria was somewhat affected. A large part of the bacteria were also lost during the acoustophoretic run. In spite of the problems, separation and detection of the bacteria seemed to work relatively well for
an unoptimized system.},
  author       = {Punkkinen, Matleena},
  language     = {eng},
  note         = {Student Paper},
  title        = {Acoustophoretic sample preparation for PCR in sepsis diagnostics},
  year         = {2013},
}