Karyotyyppitystä

Karyotyyppitys, or karyotyping, is a process used in genetics to examine an organism's chromosomes. It involves obtaining a sample of cells, typically from blood, bone marrow, or amniotic fluid, and then culturing these cells to stimulate division. During cell division, specifically metaphase, the chromosomes are most condensed and visible. The cells are then treated with a chemical to arrest them at this stage. Following this, the chromosomes are stained and photographed. These photographs are then arranged in a specific order, usually by size and banding pattern, to create a karyotype. This visual representation allows geneticists to identify any abnormalities in chromosome number or structure. Such abnormalities can include aneuploidies, where there is an extra or missing chromosome (e.g., Down syndrome, caused by an extra copy of chromosome 21), or structural rearrangements like translocations or deletions. Karyotyping is a crucial diagnostic tool in prenatal screening, cancer diagnosis, and the investigation of developmental disorders and infertility. It provides a comprehensive overview of an individual's chromosomal makeup. The process is relatively straightforward but requires specialized laboratory equipment and expertise. The resulting karyotype is a standardized representation that aids in genetic counseling and further research.