Basically, cytogenetics is the study of the structure of the chromosomes. In cytogenetic tests, chromosomes are examined using different banding techniques. Karyotype is simply a picture of a person’s chromosomes that can be studied by their number and structure. The test can be performed on blood, fetal (amniotic and placental) specimens or bone marrow. To prepare a karyotype, cells are initially cultured then in a food-rich environment they are forced to stop at a stage in the cell cycle where the chromosomes are detectable. Next, the chromosomes are stained and carefully examined under a microscope by an experienced cytogeneticist.