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.
©
The University of Kansas Medical Center