Buccal smear

:Normal range

M: Barr bodies absent

F : Barr bodies present

Comment: Barr bodies (sex chromatin) found in the nuclei of cells represent the inactivated second X-chromosome. The number of Barr bodies is one less than the karyotype. Thus in Turner’s syndrome (single X female) no sex chromatin is found, whilst it is present in Klinefelter’s syndrome XXY male

Sample: Buccal mucosa scraped and fixed