Open AccessChip calorimetry and biomagnetic separation: Fast detection of bacterial contamination at low cell titers
Author(s) -
Lerchner Johannes,
Schulz Anne,
Poeschel Theresa,
Wolf Antje,
Hartmann Tom,
Mertens Florian,
Boschke Elke
Publication year - 2012
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201200029
Subject(s) - calorimeter (particle physics) , bacteria , microorganism , calorimetry , contamination , chromatography , lab on a chip , resolution (logic) , chemistry , magnetic separation , volume (thermodynamics) , chip , magnetic nanoparticles , analytical chemistry (journal) , materials science , microfluidics , nanotechnology , nanoparticle , biology , physics , ecology , computer science , thermodynamics , artificial intelligence , detector , engineering , optics , genetics , quantum mechanics , metallurgy , electrical engineering
We present a new chip calorimeter for fast and quantitative measurement of metabolic heat rates of microorganisms attached to magnetic beads. In biomagnetic separation (BMS) experiments, Escherichia coli K12 immobilized on nonspecifically functionalized beads has a specific heat rate of around 1 pW per cell at 37°C. Therefore, at least 2 × 10 4 bacteria are required to exceed the calorimetric signal resolution of 20 nW. If the samples to be analyzed have the original volume of 4 mL, bacteria at less than 10 4 cells mL −1 should be detectable. In practice, we achieved the detection of approximately 2 × 10 4 cells mL −1 . The method presented here might also find some applications in the investigation of biofilms and study of biomolecular interactions.