Colcemid Solution (N-Deacetyl-N-methylcolchicine) is commonly used in chromosome analysis during lymphocyte karyotyping. It arrests cells in metaphase so the chromosomes can be separated for further investigation. Colcemid is related to colchicine but is less toxic. Colcemid depolymerizes microtubules and limits their formation. Appropriate dilutions inactivate the spindle fiber formation, thus arresting cells in metaphase, and allowing cell harvest and karyotyping to be performed.