Sex Chromatin 365 



(Klinger and Liidivig). In the Feiilgen method, the sex chromatin 

 stains more deeply than any other Feiilgen-positive material present. 

 Skin biopsies are reliable if the sections are of good quality, but 

 the simplest specimens are oral scrapings, easy to obtain and equally 

 easy to stain. Scrape the mucosa of the check with a tongxie depressor 

 and smear scrapings on an albumen-coated slide. Fix immediately in 

 Davidson's or alcohol. Papanicolaou fixative (equal parts of ether 

 and 95% alcohol) also may be used. 



Lennox (1956) 



fixative: 10% formalin or mercuric chloride saturated formalin. Avoid 

 Bouin's and dichromate fixatives. 



solutions: 

 Ribonuclease: 



ribonuclease 1.0 gm. 



distilled water, glass-distilled 100.0 ml. 



Boil 3-5 seconds after dissolving. Keeps about 1 week in refrigerator. 



Gallocyanin: 



chrome alum 5.0 gm. 



distilled water 100.0 ml. 



Dissolve and add: 



gallocyanin 0.15 gm. 



Shake thoroughly, heat slowly and boil 5 miniues. Cool, filter and 

 wash through filter with distilled water initil filtrate reaches 100 ml. 



*t5 



Usable at once. Keeps about 1 month. 



procedure: 



1. Deparaffinize and hydrate slides to water. 



2. Incubate in ribonuclease solution, 37°C: 10-15 miniues. 



3. Rinse in distilled water. 



4. Stain in gallocyanin, 37 °C: overnight. 



5. Dip in acid alcohol (few drops HCl in 70%, alcohol) to clean, not 

 to differentiate. 



6. Wash in tap water: 5 minutes or longer. 



7. Dehydrate, clear and mount. 



results: 



By extracting with ribonuclease, the nuclear picture is sharpened 

 against a colorless backgroinid, making it easier to distinguish the sex 

 chromatin nodule. 



