Editing Karyotype (section)

=== Staining ===

The study of karyotypes is made possible by [[staining]]. Usually, a suitable [[dye]], such as [[Giemsa]],<ref>A preparation which includes the dyes Methylene Blue, Eosin Y and Azure-A,B,C</ref> is applied after [[Cell (biology)|cells]] have been arrested during [[cell division]] by a solution of [[colchicine]] usually in [[metaphase]] or [[prometaphase]] when most condensed. In order for the [[Giemsa]] stain to adhere correctly, all chromosomal proteins must be digested and removed. For humans,  [[white blood cells]] are used most frequently because they are easily induced to divide and grow in [[tissue culture]].<ref name="Gustashaw K.M 1991">Gustashaw K.M. 1991. Chromosome stains. In ''The ACT Cytogenetics Laboratory Manual'' 2nd ed, ed. M.J. Barch. The Association of Cytogenetic Technologists, Raven Press, New York.</ref> Sometimes observations may be made on non-dividing ([[interphase]]) cells. The sex of an unborn [[fetus]] can be predicted by observation of interphase cells (see [[Amniocentesis|amniotic centesis]] and [[Barr body]]).