An integrated system for continuous assessment of intercellular pH

In this work we present a system that is capable of autonomously recording the pH of cultured cells in an incubator. The system is composed of an ion sensitive field effect transistor (ISFET), a transimpedance amplifier circuit, and a BeagleBone Black® computer which records ISFET output measurements. Cultured cells were grown directly on top of the ISFET, and the current output was converted to voltage via a transimpedance amplifier circuit. These converted voltage measurements were then recorded at user specified sampling rate. The system is completely self-contained with no need to run wires or cables from the inside of the incubator to the outside. We have demonstrated the system by observing cancer cell (human adenocarcinoma) proliferation over a 20 hour testing period.