Human Karyotype

Karyotype is a composition of one’s chromosomes. The normal karyotype is 44 autosomes and 2 sex chromosomes. Men’s sex chromosomes are XY, woman’s XX. The normal karyotype for man is 46,XY and for woman 46,XX.

Blood, marrow, skin, amniotic fluid or chorion cells are used to state the karyotype. In a cell culture, division stimulating substances are added to promote cell growth. Colchicine, which precludes formation of the spindle and stops mitosis in metaphase, is added. Next, the cells are made to swell by adding a solution. As a result chromosomes separate. They are colored afterwards and homologous chromosomes receive their characteristic pattern.

There are also other methods for stating the karyotype.