ELLIPSIN 



115 



ENAMEL 



cal Library, Inc., 1944, 332 pp. Under 

 favorable conditions some kinds of 

 of elementary bodies are visible at high 

 magnification unstained by both direct 

 and dark field illumination. Supra- 

 vital stains such as brilliant crcsyl blue, 

 neutral red, methylene blue and azur II 

 are recommended. Before staining 

 smears, fixed in a variety of ways, pre- 

 treatment with 2.5% aq. potassium per- 

 manganate or 2% aq. chromic acid is 

 advised. Giemsa stain gives good re- 

 sults but the methods of Paschen, Moro- 

 sow and Herzberg are suggested by 

 Seiffert. The fluorescence technique 

 of Hagemann consists of staining thin 

 air dried smears with 1 gm. primuline 

 dissolved in 1000 cc. aq. dest. + 20 cc. 

 pure phenol for 15 sec. washing in aq. 

 dest. and observation in ultraviolet 

 light by fluorescence microscope. 



New methods for the collection and 

 purification of elementary bodies permit 

 their direct examination at very high 

 magnifications with the electron micro- 

 scope (von Borries, E. G., Ruska, E. 

 and H., Klin. Woch., 1938, 17, 921 ; Green, 

 R. H., Anderson, T. F., and Smadel, 

 J. E., J. Exp. Med., 1942, 75, 651-656) 

 and their chemical analysis for vitamin 

 catalysts, copper and enzymes (Hoag- 

 land, C. L., Ward, S. M., Smadel, J. E., 

 and Rivers, T. M., J. Exp. Med., 1942, 

 76, 163-173). See fluorescence of ele- 

 mentary bodies (Turevich, E. I. ab- 

 stracted in Stain Techn., 1941, 16, 182.) 



Ellipsin is structure protein of cells. Meth- 

 ods for its isolation from liver cells of 

 rabbit and guinea pig by grinding fresh 

 tissue, washing, centrifugation and so 

 on are fully described by Bensley, R. R. 

 and Hoerr, N. L., Anat. Rec, 1934, 60, 

 251-266. 



Embedding, see Imbedding. 



Embryo Chick, see Chorioallantoic Mem- 

 brane. 



Embryological Methods. In general the 

 techniques which give good results with 

 adult tissues are also satisfactory for 

 embryos ; but there are differences as for 

 example in silver impregnations. More- 

 over greater care is necessary to avoid 

 too sudden changes in the fluids used. 

 Helpful suggestions are given in Mc- 

 Clung, pp. 279-286. Application of 

 trichrome staining methods to embryos 

 (Baxter, J. S., J. Anat., 1940-41, 75, 

 137-140). See demonstration of Car- 

 tilaginous Skeleton, Ossification and 

 Spalteholz method. Technique for 

 handling chick embryos (Adamstone, 

 F. B., Stain Techn., 1931, 6, 41-42). 

 Block staining of nervous tissue of em- 

 bryos with silver (Davenport, II. A., 

 Stain Techn., 1934, 8, 143-149). 



Emission Electron Microscopy, see Electron 

 Microscopy. 



Enamel (dental). This can best be studied 

 in ground sections of Teeth. 1. Cuticle. 

 Wash and brush tooth in tap water. 4% 

 neutral formalin, 24 hrs. Wash tap 

 water, 24 hrs. Mallory's anilin blue 

 (0.5% aq.) 24 hrs. Again wash and 

 brush in tap water. 10% aq. hydro- 

 chloric acid, 10 min. As enamel is dis- 

 solved delicate opaque white membrane 

 appears. Tease membrane off onto slide 

 coated with egg albumen (Albumen- 

 Glycerin). Blot with filter paper. 5% 

 aq. sodium thiosulphate or bicarbonate 

 10 min. Wash in tap water 10 min. 

 Dehydrate in alcohols, clear in xylol 

 and mount in gum damar (McClung, 

 p. 371). 



2. Rods. Macerate tooth in 5-10% 

 aq. hydrochloric acid for 24 hrs. Re- 

 move a little softened enamel and 

 examine (McClung, p. 372). See Chase, 

 S. W., Anat. Rec, 1927, 36, 239-258. 



3. Organic Matrix. Boedeker's 

 method abbreviated from McClung (p. 

 372). Dehydrate small piece (0.5- 

 1 mm. thick), free from dentin, through 

 alcohols 10 min. each. Methyl alcohol 

 1-2 hrs. Decalcify in celloidin mixture 

 (parlodion, DuPont) made by dissolving 

 sufficient in methyl ale. C.P. to give 

 thick syrupy solution. To 150 cc. of 

 this add drop by drop constantly stir- 

 ring nitric acid C.P., 10 cc. -f methyl 

 ale. 40 cc. Keep tissue in this mixture 

 in glass dish with air tight cover. Or- 

 ganic matrix appears as brown, spongy 

 material in 10-12 hrs. care being taken 

 to leave the dish stationary. After 

 decalcification is completed, 2-7 days, 

 uncover and permit celloidin to harden. 

 Cut out specimen with narrow margin of 

 celloidin. 70 and 40% ale. 1-2 hrs. each. 

 Aq. sol. alum, 24 hrs. Running water, 

 6-12 hrs. Ascending alcohols to 95% 

 1-2 hrs. each. Anilin oil, 6-12 hrs. 

 (becomes brown and transparent). 

 Equal parts anilin oil and chloroform, 

 6-12 hrs. Imbed in paraffin not over 

 52°C. Mount 3-10^ sections, dry and 

 treat with xylol 3 min. Dissolve cel- 

 loidin in ether-alcohol. Abs. ale. 1 

 min. Descending alcoliols to water. 

 Stain in Iron Hematoxylin. 



Improved results may be obtained by 

 slow decalcification and concurrent fixa- 

 tion as described b.y Sognnaes, J. Dental 

 Res., 1949, 28, 558-564. Teeth are 

 placed in celloidin bags filled with 10% 

 formalin and immersed in a solution of 

 5 gm. trichloroacetic acid, 2^ gm. po- 

 tassium bichromate in 100 cc. distilled 

 water. Ten centimeter of formalde- 

 hyde is added to the solution. Decalci- 

 fication of enamel is completed after 



