A single unit pH glass ultramicro electrode

Summary

The single unit glass ultramicro electrode can measure the pH of a sample of less than 0.05 μl in volume. The single unit electrode is advantageous in in vivo micropuncture work. It eliminates the need for double penetration of the tissue with both the indicator and the reference electrode. The physical combination of the glass indicator half-cell with the reference half-cell permits the pair to establish contact with the solution at almost the same point, thus avoiding the incorporation of spatial potentials not due to cationic activities.