Cell culturing system, sensor kit, and method of determining lifespan of enzyme sensor

A sensor kit, comprising:

• an enzyme sensor configured to detect a concentration of a predetermined component of a culture medium used for culturing of cells;
• and
• a sensor flow path extended from a first end and a second end of the enzyme sensor, wherein the sensor flow path is made up from a thermoplastic tube that is closed at the first end and the second end and that is configured to be aseptically joined to a flow path through which the culture medium of a cell culturing system flows;
• a processor;
• and
• memory including a program, that when executed by the processor causes the processor to:
• determine a concentration value of the predetermined component of the culture medium based on output of the enzyme sensor;
• determine a deterioration index of the enzyme sensor by multiplying the concentration value of the predetermined component of the culture medium by a detection period during which the enzyme sensor detects the concentration value;
• and
• determine a lifespan of the enzyme sensor based on whether the deterioration index has reached a threshold value.