title: Optical non-contact pH measurement in cell culture with sterilizable, modular parts.
abstract: A non-contact real time pH measurement using fully modular optical parts is described for phenol-red medium cell cultures. The modular parts can be sterilized, and once the measurement is started at the beginning of culture, no recalibration or maintenance is needed till the end of the culture. Measurements can be carried out without any special manual attention. The modular assembly of LED and sensor cassettes is unique, robust, reusable and reproducible. pH is measured in an intact closed flow system, without wasting any culture medium. A special pump encapsulation enables the system to be effortlessly functional in extremely humid incubator environments. This avoids lengthy sample tubings in and out of the incubator, associated large temperature changes and CO2buffering issues. A new correction model to compensate errors caused e.g. by biolayers in spectrometric pH measurement is put-forward, which improves the accuracy of pH estimation significantly. The method provides resolution down to 0.1 pH unit in physiological pH range with mean absolute error 0.02.
authors: Department of Automation Science and Engineering, Tampere University of Technology, Tampere, Finland. Electronic address: dhanesh.kr@tut.fi.
authors: Dhanesh
authors: D
authors: Kattipparambil Rajan
authors: Adult Stem Cell Group, BioMediTech, Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland; Science Center, Tampere University Hospital, Tampere, Finland. Electronic address: mimmi.patrikoski@staff.uta.fi.
authors: Mimmi
authors: M
authors: Patrikoski
authors: Department of Automation Science and Engineering, Tampere University of Technology, Tampere, Finland. Electronic address: jarmo.verho@tut.fi.
authors: Jarmo
authors: J
authors: Verho
authors: Adult Stem Cell Group, BioMediTech, Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland; Science Center, Tampere University Hospital, Tampere, Finland. Electronic address: jyrki.sivula@outlook.com.
authors: Jyrki
authors: J
authors: Sivula
authors: Department of Automation Science and Engineering, Tampere University of Technology, Tampere, Finland. Electronic address: heimo.ihalainen@tut.fi.
authors: Heimo
authors: H
authors: Ihalainen
authors: Adult Stem Cell Group, BioMediTech, Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland; Science Center, Tampere University Hospital, Tampere, Finland. Electronic address: susanna.miettinen@staff.uta.fi.
authors: Susanna
authors: S
authors: Miettinen
authors: Department of Automation Science and Engineering, Tampere University of Technology, Tampere, Finland. Electronic address: jukka.lekkala@tut.fi.
authors: Jukka
authors: J
authors: Lekkala
mesh_terms: D000273:Adipose Tissue / Q000166:cytology; D018929:Cell Culture Techniques / Q000379:methods*; D005260:Female; D005347:Fibroblasts; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008875:Middle Aged; D010637:Phenolsulfonphthalein; D066330:Printing, Three-Dimensional; D013234:Stem Cells; D013242:Sterilization; D013696:Temperature
chemical_list: D007202:Indicators and Reagents; D010637:Phenolsulfonphthalein
keywords: Cell culture non-contact pH measurement; Cell culture optical pH measurement; Cell culture pH measurement; Long term pH measurement; Phenol red medium pH measurement