Sex chromatin scores in oral mucosa and hair root sheaths of human females.

The preparation and the utility of oral mucosa and hair root sheaths for quantitative sex chromatin studies is discussed. In buccal smears requirements for reliable scoring are frequently not fulfilled. Counting is time-consuming and disturbing measurement errors cannot be avoided. On the other hand, hair root sheath slides can be quickly prepared, the method yields preparations of good quality, and sex chromatin is displayed with considerable clarity. This procedure thus provides a high degree of accuracy and simplicity and counting can be quickly done with a relatively small measurement error. The incidence of sex chromatin in hair nuclei is observed to be about 20 per cent higher than in oral mucosa of the same female. In hair root sheaths non-peripheral sex chromatin can easily be recognized; including these into the scores significantly increases the actual incidence of sex chromatin positive nuclei.