Figure 1.

(a) Schematics of a GUV containing LUVs filled with catechol. Catechol release (iv) upon LUV fusion to the GUV membrane is detected by a carbon fiber electrode (v). The expanded view provides details of DNA mediated exocytosis. Injection and self-insertion of CH-DNA b/b' (red) into the GUV membrane was followed by a second injection of catechol-filled LUVs decorated with the complementary CH-DNA a/a' (black). The DNA strands hybridize in a zipper-like fashion and bring about fusion of the two membranes. Cartoons are not drawn to scale. (b) Nomarski image of a GUV, with a multilamellar bleb, attached as a lipid reservoir, a microinjection pipette electroinserted into the interior of a GUV (i), electrode for electroinsertion (ii) and a 5-µm diameter amperometric electrode, beveled to a 45° angle (iii). (c) Amperometric recording of repeated exocytosis events at the secretory cell model, the apparent delay in release in due to reposition of the electrode (upper trace). The lower trace represents amperometric monitoring after injection of vesicles that do not display CH-DNA. The arrow indicates the start of Ca²⁺ addition. The inset shows a single exocytosis event spike at an expanded time scale.