Barr test
The Barr test is a test of a person's sex chromatin . This test can be used to determine whether a person genetically corresponds to the female genotype, i.e. whether they have two X chromatins (compare intersexuality ). Such sex determination is mainly carried out in female athletes , as some intersexual syndromes associated with XY chromosomes but a female body presumably lead to physical advantages over XX women; therefore, intersex people are often excluded from athletic competitions.
For this purpose, it checks if a so-called Barr body ( Barr body ) in the nucleus of a cell is present, the person under examination. For example, the cells of the hair root sheath can be examined for rapid tests . The test candidates only have to pull out a few hairs. If, after a special treatment with Feulgen staining (blue-purple hue), only a single Barr body is present in the microscopically observed cell nuclei , it is a "normal" woman or a person with Klinefelter syndrome . If there is no Barr body, it is either a man or a woman with Turner syndrome or androgen insensitivity or other IS syndromes. If there are two Barr bodies, a woman has triple X syndrome . In 1992 the test was replaced by the polymerase reaction test.
Individual evidence
- ↑ Michael Kent: Advanced Biology . OUP Oxford, 6 July 2000, ISBN 978-0-19-914195-1 , pp. 427-.