Setting up an enucleation pipette. The procedure is the same for injection pipettes (see text for details). Note that the PVP drop and pipette are under oil. (A) Air is expelled from the tip of the enucleation/injection micropipette; the tip is washed several times with oil and then with PVP medium (B) until the mercury is moved smoothly inside the pipette. (C) A small volume of oil is placed between the PVP and the CZB-HEPES medium to prevent the mercury from contaminating the micromanipulation medium.