Fig. 6.
A–C. HPF/FS vs conventional specimen preparations for untreated PtK1 cells. A Adjacent kinetochores from a conventionally prepared metaphase cell. Note the prominent outer plate (op) structure that stains as heavily as chromatin, and is separated from the underlying inner plate (ip) by a well-defined, translucent, middle layer (ml).Microtubule (Mt) plus ends can not be clearly traced within the highly condensed outer plate. B, C Two different kinetochores from an anaphase cell prepared via HPF/FS. Note the absence of a prominent outer plate. Instead there is a lightly staining mat structure that sits above the chromatin without an intervening translucent layer. Mt plus ends can be traced (small black arrows) and they appear to flay apart and be continuous with the fibrous mat (in agreement with Mastronarde et al. 1997). The cytoplasmic exclusion zone can still be detected in some areas where there are no Mts (large black arrows). The mottled appearance of the centromeric heterochromatin is also evident (white arrows). Bar represents 200 nm