of the number and structure of the chromosomes when cell division has been
arrested and the chromosomes stained at an early stage (pro-metaphase) of
mitosis. The chromosomes of a high resolution study appear longer and reveal
700-1200 bands, allowing more detailed analysis of the chromosome structure,
as opposed to the typical 300-600 bands observed with routine metaphase banding.
Definition from: GeneReviews
from the University of Washington and the National Center for Biotechnology Information
See also Understanding Medical Terminology.