Cytogenetic technologists typically work with cells (from blood, bone marrow, amniotic fluid, etc.) that are grown in culture, arrested at a specific stage of cell division (metaphase), and then stained and viewed under a microscope. They create karyotypes, which are organized arrangements of a person's chromosomes, to identify large-scale chromosomal abnormalities like missing or extra chromosomes (e.g., Down syndrome, space waves), large deletions, duplications, inversions, or translocations.