TRANSMISSION ELECTRON-MICROSCOPY OF CHROMOSOMES BY LONGITUDINAL SECTION PREPARATION - APPLICATION TO FRAGILE-X CHROMOSOME ANALYSIS

We developed a method for the preparation of ultrathin longitudinal se ctions of chromosomes enabling TEM studies of whole chromosomes. By us ing a novel ''repeat chill'' method of exposing the glass slide and pl astic block interface to liquid nitrogen, it was possible to separate consistently hardened epoxy resin-embedded chromosome spreads from gla ss slides for ultrathin longitudinal sectioning of entire spreads and of individual chromosomes. The method was applied to analyze the fragi le X chromosome, The ultrastructure of centromeres, telomeres, fragile sites and other chromosomal areas can now be studied in detail. (C) 1 997 Wiley-Liss, Inc.