SECTION TWO 



Results : 



The sex chromatin is visible only in the nucleus from the 

 female. 



Notes: 



{a) The author (Moore) states that a minimum of one hundred 

 nuclei, selected at random should be examined for the presence 

 of sex chromatin. The sex chromatin is most definite and easiest 

 to recognize when it is located adjacent to the nuclear membrane. 

 It is about one micron in diameter and is usually round or plano- 

 convex. In occasional smears the sex chromatin is flattened 

 against the nuclear membrane, and in consequence it is less 

 conspicuous than usual. Unmistakable sex chromatin is visible 

 in 30 to 60% of nuclei of chromosomal females, but nuclei of 

 chromosomal males rarely present a mass of chromatin which 

 can be recognized as sex chromatin. 



(b) The author observes that it is difficult to differentiate a 

 female infant with congenital adrenogenital syndrome from a 

 male with pseudohermaphroditism, and it is important to make 

 this distinction early to prevent metabolic disturbances : knowledge 

 of chromosomal sex is a helpful guide in cases of doubt. 



(c) The original paper should be consulted for more detailed 

 information, including a number of colour plates. Moore's 1959 

 paper should also be consulted. 



References: 



Moore, K. L. (i960). 

 Moore, K. L. (1959). 



CRESYLFAST VIOLET - TOLUIDINE BLUE - THIONIN 



(EHRLICH) 



A non-fading tri-basic stain for nerve cells and Nissl 

 granules, in normal and pathological tissues 



Solutions required: 



A. Cresylfast violet, CNS . . . , 2 gm. 



Toluidine blue . . . . . . i[gm. 



Thionin (Ehrlich) . . . . . . 0-5 gm. 



Ethyl Alcohol 30% . . . . . , 200 ml. 



183 



