The process of karyotyping begins with collecting a sample of cells, usually through a blood sample, amniocentesis, or bone marrow biopsy. The cells are then cultured to encourage them to divide. When the cells reach metaphase, they are treated with a chemical to halt the division. The chromosomes are stained, usually with a dye such as Giemsa, which produces a characteristic banding pattern. The stained chromosomes are then photographed under a microscope, and the images are arranged into a karyotype for analysis.
