A pictorial presentation of an individual’s chromosomes, taken from microphotographs (photographs taken through a microscope) and arranged in a numeric sequence that aligns the chromosomes from largest to smallest. This standardized presentation allows the geneticist to analyze an individual’s chromosomal profile. A geneticist can structure a karyotype from any SOMATIC CELL (nonsex cell) in the body. The most common application of karyotyping is GENETIC SCREENING of a fetus. A geneticist constructs a karyotype to evaluate whether an individual has a GENETIC DISORDER. A karyotype requires DNA from a representative cell in the body, from which the geneticist extracts and prepares the DNA for examination under the microscope.