Live Imaging of Drosophila Larval Salivary Glands

Live imaging of larval salivary glands was performed as previously reported (Tran et al., 2015 (link)). In short, naturally secreting isolated glands were placed in a glass-bottom imaging dish, covered with a Isopore 0.1 µm PC membrane (Merck) and 50 µl Schneider's Drosophila medium. For long-term imaging, the imaging chamber was humidified with a wet tissue paper and sealed with parafilm to prevent evaporation. Dissected glands were imaged with a Zeiss CellObserver Z.1 with a Yokogawa CSU-X1 spinning disc scanning unit and an Axiocam MRm CCD camera (6.45 µm×6.45 µm). For additional Dextran imaging, dissected glands were incubated for 1 h with 200 µM Dextran-Alexa568 (molecular mass 10,000, Invitrogen) in Schneider's Drosophila medium, washed three times with medium and then placed on an imaging chamber as described above.