Sources of error in measuring tissue pH with microsensors

The use of pH microsensors in tissue is complicated by a rise in pH over a given period of time. One explanation for this occurrence is that the formation of a layer of protein on the surface of a glass electrode may affect the recorded pH. Experiments were designed to study the effect of both a uniform and nonuniform coating of fibrinogen on pH. A uniform coating is seen to affect the recorded value to a greater degree than a nonuniform coating. If a sensor does acquire a uniform layer of protein upon placement in tissue, then this error needs to be further addressed to obtain accurate pH measurements