Microoxygraph Device for Biosensoristic Applications

Figure 7

Typical cell OCR test by microoxygraph chip. 3T3 cells (1.8 × 10⁴ cells/microchamber) were seeded in microoxygraph chamber and incubated for 12 h. After DMEM replacement with L15, amperometric measurements were performed. The recorded current is proportional to the dissolved oxygen concentration (directly) and to the cell OCR (inversely). The slope of oxygen concentration with time is defined as the oxygen consumption rate. Blue and red lines evidence the slopes before and after electron transport chain-inhibitor injection, respectively. Black arrow: 20 mM NaN₃ injection. The recorded OCR, directly proportional to the number of active cells, is characterized by an initial high speed that slightly decreases after 150 sec. This positive O₂ consumption trend is congested by NaN₃ cell intoxication (a). Optical image of the 3T3 cells acquired after the recorded metabolic impairment. Plump morphology is observable in mitochondrial toxin damaged cells; cathode is clearly visible under cell culture OPM (b).

(a)

(b)