Imaging and quantification of apical microvilli in the syncytial blastoderm of Drosophila embryos

The syncytial Drosophila blastoderm embryo contains apical microvilli with filamentous actin that are remodeled during nuclear division cycles 10–13. Here, we describe a protocol for preparing whole embryo samples and capturing images of microvilli using confocal and super-resolution STED microscopy. This protocol enables visualization and quantification of lengths and numbers of microvilli oriented along the imaging plane. We provide information on identifying different nuclear division cycles and examples of quantification from the interphase and metaphase of cycle 12.