title: Non-invasive measurement of cell membrane associated proton gradients by ion-sensitive field effect transistor arrays for microphysiological and bioelectronical applications.
abstract: The pH in the cellular microenvironment (pH(M)) is an important regulator of cell-to-cell and cell-to-host interactions. Additionally the extracellular acidification rate of a cell culture is an important indicator of global cellular metabolism. In a new approach a biocompatible ion-sensitive field effect transistor (ISFET)-array was developed to measure the pH(M) close to a surface and the global extracellular acidification rate at the same time. This ISFET-array is part of a new multiparametric microsensor chip. The paper highlights some basic applications of this method for in-vitro measurements. Using a fluid perfusion system for cell culture media, it is possible to measure the pH(M) of few (five to ten) adherent tumor cells in a distance of 10-100 nm from the cell plasma membrane. Experiments showed a pH(M)-value of 6.68 +/- 0.06 pH. Further experiments suggest that both the low pH, and the extracellular acidification rate of the examined tumor cell line are mainly built up by glycolysis.
authors: Universitat Rostock, Biophysik, Germany.
authors: M
authors: M
authors: Lehmann
authors: W
authors: W
authors: Baumann
authors: M
authors: M
authors: Brischwein
authors: R
authors: R
authors: Ehret
authors: M
authors: M
authors: Kraus
authors: A
authors: A
authors: Schwinde
authors: M
authors: M
authors: Bitzenhofer
authors: I
authors: I
authors: Freund
authors: B
authors: B
authors: Wolf
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D014407:Tumor Cells, Cultured