karüotüüping

Karüotüüping is a laboratory technique used to examine an individual's chromosomes. It involves collecting a sample of cells, typically from blood, but can also be from amniotic fluid, bone marrow, or other tissues. These cells are then cultured in a laboratory to stimulate cell division. During a specific phase of cell division called metaphase, the chromosomes are most condensed and visible. The cells are treated to arrest them in this phase, and then the chromosomes are stained and spread out on a slide. A photograph is taken of these chromosomes, and they are then arranged in homologous pairs according to size, banding pattern, and centromere position. This organized display is called a karyotype.

The primary purpose of karüotüüping is to detect chromosomal abnormalities. These abnormalities can include changes in chromosome number, such as aneuploidy (e.g., Down syndrome, caused by an extra copy of chromosome 21) or polyploidy (having more than the usual two sets of chromosomes). It can also identify structural abnormalities, such as deletions (missing parts of chromosomes), duplications (extra copies of chromosome segments), translocations (where parts of chromosomes have broken off and reattached to other chromosomes), and inversions (where a segment of a chromosome has been flipped). Karüotüüping is a valuable tool in diagnosing genetic disorders, assessing fertility issues, and in prenatal diagnosis. It can also be used in cancer research to identify chromosomal changes in tumor cells.