====== Karyotyping ======
Karyotyping should be done during the metaphase cycle, when the chromosomes are distinct and easily counted.  To obtain a sample with a good number of cells in metaphase, typically blood or skin cells are collected.  Some drugs are used to stimulate division and lock cells into metaphase: see [[http://arbl.cvmbs.colostate.edu/hbooks/genetics/medgen/chromo/cytotech.html|Preparing a Karyotype]].

Another procedure done here: [[http://faculty.virginia.edu/xtropicalis/KaryotypeXtropicalis.htm|Karyotyping X. tropicalis]] to karyotype a species of frog, simply stains cells in the tadpoles, which are already actively dividing.