Fig. 1.

Filipin staining of the chlamydial inclusion. At 20 h p.i., HeLa cells were gently fixed with paraformaldehyde and incubated with filipin for 30 min for visualization of cholesterol. Images were acquired at different focal planes to allow visualization of the chlamydial developmental forms (A) and the inclusion membrane (B). The inclusion membrane typically stains much brighter than the chlamydiae. Images of RBs were therefore acquired first so as to compensate for the effects of photobleaching. Arrowheads indicate the inclusion membrane. (C) Nomarski differential interference contrast image of the same field. Scale bar, 1 μm.