Fluorescence microscopy of live worms

Worms were collected, washed with M9 buffer (22 mM KH₂PO₄, 22 mM Na₂HPO₄, 85 mM NaCl, 1 mM MgSO₄), and then immobilized with 10 mM sodium azide (S2002, Sigma-Aldrich) in M9 buffer. After removing the buffer, drop worms were placed on microscope cover glasses (HSU-0101242; Marienfeld Laboratory Glassware, Lauda-Königshofen, Germany), and covered with a coverslip. All images were obtained using Olympus FV1000 confocal laser scanning microscopy (Olympus, Tokyo, Japan).