title: Ultrasonic manipulation of yeast cells in suspension for absorption spectroscopy with an immersible mid-infrared fiberoptic probe.
abstract: Recent advances in combining ultrasonic particle manipulation with attenuated total reflection infrared spectroscopy of yeast suspensions are presented. Infrared spectroscopy provides highly specific molecular information about the sample. It has not been applicable to in-line monitoring of cells during fermentation, however, because positioning cells in the micron-thin measurement region of the attenuated total reflection probe was not possible. Ultrasonic radiation forces exerted on suspended particles by an ultrasonic standing wave can result in the buildup of agglomerates in the nodal planes, hence enabling the manipulation of suspended cells on the microscopic scale. When a chamber setup and a prototype in-line applicable probe were used, successful control over the position of the yeast cells relative to the attenuated total reflection sensor surface could be proven. Both rate of increase and maximum mid-infrared absorption of yeast-specific bands during application of a pushing frequency (chamber setup: 1.863 MHz, in-line probe: 1.990 MHz) were found to correlate with yeast cell concentration.
authors.affiliation: Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria.
authors.forename: Cosima
authors.initials: C
authors.lastname: Koch
authors.forename: Markus
authors.initials: M
authors.lastname: Brandstetter
authors.forename: Bernhard
authors.initials: B
authors.lastname: Lendl
authors.forename: Stefan
authors.initials: S
authors.lastname: Radel
mesh_terms: D002469:Cell Separation / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D008846:Micromanipulation / Q000295:instrumentation*; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification* / Q000378:metabolism*; D013010:Sonication / Q000295:instrumentation*; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation*; D014159:Transducers
references.citation: Trends Biotechnol. 1997 Dec;15(12):506-11
references.pmid: 9418305
references.citation: Bioseparation. 2000;9(6):369-77
references.pmid: 11518240
references.citation: J Appl Microbiol. 1997 Jan;82(1):39-47
references.pmid: 9113876
references.citation: Trends Biotechnol. 2003 Feb;21(2):89-93
references.pmid: 12573858
references.citation: Arch Dis Child. 1998 Jan;78(1):58-60
references.pmid: 9534678
references.citation: Anal Sci. 2009 Feb;25(2):285-91
references.pmid: 19212067
references.citation: Biosens Bioelectron. 2004 Apr 15;19(9):1021-8
references.pmid: 15018957
references.citation: Ultrasonics. 2000 Mar;38(1-8):633-7
references.pmid: 10829741
references.citation: Ultrasonics. 2010 Feb;50(2):240-6
references.pmid: 19883932
references.citation: Anal Chem. 2004 Nov 1;76(21):6353-8
references.pmid: 15516127
references.citation: Bioseparation. 2000;9(6):329-41
references.pmid: 11518236
references.citation: Ultrasound Med Biol. 2005 Feb;31(2):261-72
references.pmid: 15708466