IST1 structures form in absence of serum and tightly adhere to the cell substrate. (A) Confocal micrographs of monocyte-derived dendritic cells (moDCs) cultured in the presence or absence of 10% fetal bovine serum, on glass coverslips that are either uncoated, coated with rat tail collagen, fibronectin, or poly-L-lysine (PLL). Yellow arrowheads indicate IST1 structures. (B) MoDCs cultured in the presence of serum were harvested with cold-procedure and subsequently reseeded on clean coverslips in the absence of serum. Confocal micrograph of reseeded moDC immunolabeled for IST1 (magenta), phalloidin (green), and DAPI (blue). (C) MoDCs were cultured overnight on coverslips in the absence or presence of serum, and cells were subsequently harvested using cold-procedure. Confocal micrographs of residue on the coverslips. To ensure imaging at the right z-plane, areas with a remaining cell (i.e., with a nucleus) are shown. Scale bars: 10 μm.