Non-invasive measurement of cell membrane associated proton gradients by ion-sensitive field effect transistor arrays for microphysiological and bioelectronical applications.
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.
Lehmann
M
M
Universitat Rostock, Biophysik, Germany.
Baumann
W
W
Brischwein
M
M
Ehret
R
R
Kraus
M
M
Schwinde
A
A
Bitzenhofer
M
M
Freund
I
I
Wolf
B
B
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D014407:Tumor Cells, Cultured