Technologists screen slides to find metaphases that meet the
criteria for analysis, including minimally overlapping chromosomes.
The analysis is done using a microscope with a magnification
of 1000X. This involves counting the number of chromosomes in
each metaphase, and completing a band for band analysis for each
chromosome. In order to accomplish this the technologist must
be familiar with the ideogram of each chromosome. The human ideogram,
a diagrammatic representation of a karyotype, has been determined
by an international committee of cytogeneticists. This ideogram
is based on size, centromere location and the banding patterns
of each chromosome. This standard is the basis for the analysis
of all human chromosomes. The committee has also established
a set of nomenclature that is used to describe the karyogram
of a cell.