Some Problems with an Intracellular PO₂ Electrode

Abstract

The micro O₂ electrode we have developed in our laboratory-has been described in detail (4). Briefly, the electrode is made by filling a glass capillary with a molten mixture of Wood’s metal and gold. The capillary is then drawn out with heat to a sharp point. The shank has a long taper₀ After inserting the wire contact the tip is bevelled (45° or less) on a diamond-dust-covered rotor. At the beginning of the bevel the electrode measures 2–3μ. The metal in the tip is etched away electrolytically until there is a recess of 20–40μ. On the metal in the recess a layer of gold usually 5–15μ thick, is plated. The recess is usually filled with collodion to act as a filter for large molecules. The electrode (cathode) is used in the usual way with a Ag-AgCl anode (0.7–1.0V).

This work has been supported in part by grant nos. HL 11906 and HL 12703 from the U.S.P.H.S.