Figure 3. Summary of data show the lifetime of the ATP probe over repeated usage.

Probe electrical current (pA) response to increasing doses of ATP on the first day of use to the third day of use (A). Probe responsiveness was well-maintained over 2 days of use, but began to lose sensitivity at the lower concentrations of ATP by day 3 (P > 0.05). Overall responsiveness (B) of the ATP probe declined by the third day of use.