The exceptional organization of polytene chromosomes
has made fruit fly Drosophila melanogaster a premier
model organism for visualization of genes. A major
barrier to full exploitation of polytene chromosome
cytology has been the difficulty in producing good
chromosome preparations. A new, economical procedure
using high pressure and other modifications to
overcome this barrier is presented. Light microscopy
images of such slides compared to electron
microscopy images for the first time show similar or
superior detail. Results from typical staining
applications, including...