Karüotyping

Karyotyping is a laboratory technique used to visualize and analyze the chromosomes of an organism. Chromosomes are thread-like structures found in the nucleus of cells that carry genetic information in the form of DNA. Karyotyping involves obtaining a sample of cells, such as blood or tissue, which are then cultured to encourage cell division. During cell division, specifically metaphase, chromosomes are at their most condensed and visible state. The cells are treated to arrest them at this stage, and then the chromosomes are stained and photographed under a microscope. These images are then cut out and arranged in a standardized format, typically by size, banding pattern, and shape, to create a karyotype. The resulting karyotype shows the complete set of chromosomes for an individual, arranged in homologous pairs. Karyotyping is a valuable diagnostic tool used to identify chromosomal abnormalities, such as changes in chromosome number (aneuploidy, like Down syndrome due to an extra chromosome 21) or structural rearrangements (like deletions, duplications, translocations, or inversions). These abnormalities can be associated with various genetic disorders, developmental delays, infertility, and certain types of cancer. The analysis of a karyotype helps in understanding the genetic basis of these conditions and can aid in genetic counseling and reproductive planning.