EOSIN SCARLET 



118 



EPIDERMIS 



under the microscope until the time has 

 been determined. 



Eosin Scarlet, see Eosin B or bluish. 



Eosin Scarlet B, see Eosin B or bluish. 



Eosin Y or yellowish (CI, 768). Tetrabrom 

 fluorescein with some mono- and di- 

 brom compounds. This is the usual 

 kind of eosin employed. Eosin Y and 

 thionin as substitute for Wright's stain 

 (Saye, E. B., Am. J. Clin. Path., Tech. 

 Suppl., 1943, 13, 12). 



Eosinophile Leucocyte (acidophilic or 

 coarsely granular leucocyte). Can 

 easily be examined while still living in 

 mounts of fresh blood. The dark field 

 is useful. Most frequently studied in 

 Blood Smears, which see. Mitochon- 

 dria are readily stainable with Janus 

 Green. For occasional presence of 

 basophile granules and pigment see 

 Downey, H., Folia Haemat., 1915, 19, 

 148-206. Techniques for rapid experi- 

 mental increase of eosinophiles in 

 circulating blood are described by 

 Banerji, N., Am. J. Med. Sci., 1933, 

 186, 689-693; Chillingworth, F. P., 

 Healy, J. C. and Haskins, F. E., J. Lab. 

 and Clin. Med., 1933-34, 19, 486-494; 

 Hajos, K., Nemeth, I., and Enyedy, Z., 

 Zeit. f. d. ges. Exper. Med., 1926, 

 48, 590-592. Variations and errors in 

 eosinophile counts of blood and bone 

 marrow are described by Best, W. R. 

 and Samter, M., Blood, 1951, 6, 61-74. 



Epidermis. This can be studied in situ 

 with the dermis, see Skin, or it can be 

 examined in 3 ways apart from the 

 dermis. 



1. Isolated pieces. Examination of 

 scrapings of the epidermal surface is of 

 limited usefulness in special cases. To 

 cut away a few of the deeper cells, sepa- 

 rate them by teasing and to study them 

 in the still living state with or without 

 supravital stains is not particularly 

 helpful. But their microdissection is 

 capable of giving important data on 

 cellular consistency and connections 

 (Chambers, R. and deRenyi, G., Am. 

 J. Anat., 1925, 35, 385-402 and Than- 

 hoffer, L., Zeit. f. Anat. u. Entw., 1933, 

 100, 559-562). Their cultivation is 

 possible, see Tissue Culture. 



2. Whole mounts for microscopic study 

 (Cowdry's Histology, p. 530). Place 

 excised fresh skin in 1% acetic acid in 

 ice box for 12-36 hrs. depending upon 

 size, age and region. Wash in tap water, 

 5 min. Pin skin down with epidermis 

 up and cover with water. Strip off 

 epidermis as a compete sheet. Wash in 

 aq. dest., 5 min. Stain in Harris' 

 hematoxylin, 20 min. Wash in aq. dest., 

 1 min. Differentiate in 50 cc. 70% 

 alcohol plus 3 drops hydrochloric acid 

 until epidermis becomes light pink color. 



Treat with 50 cc. aq. dest. plus 6 drops 

 ammonia until it becomes blue. Wash 

 in aq. dest. 5 min. several changes. 

 Dehydrate in 50, 70, 95 and 2 changes of 

 absolute alcohol, 10 min. each. Clear 

 in 2 changes xylol, 1 hr. each and mount 

 in balsam inner side up. 



If the skin is hairy, before excising it, 

 remove hair with scissors and electric 

 razor or depilatory solution. Hair fol- 

 licles and sebaceous glands, unless par- 

 ticularly large, generally remain at- 

 tached to the epidermis, but the coiled 

 bodies of the sweat glands are too deeply 

 situated to come off with it. Conse- 

 quently only their straight ducts are to 

 be seen. Before dehydration, in the 

 above technique the sebaceous glands 

 can be sharply counterstained with 

 Sudan IIL 



Such whole mounts of epidermal 

 sheets are of value insofar that their 

 study gives a concept of the morphology 

 of the epidermal covering of the body 

 which can be obtained in no other way. 

 For the counting of mitoses they are far 

 better than sections and have been 

 extensively employed for this purpose 

 by Dr. Cooper and her associates in The 

 Barnard Free Skin and Cancer Hospital. 

 See her latest paper (Cooper, Z. K. and 

 Reller, H. C, J. Nat. Cancer Inst., 

 1942, 2, 335-344). Since the mucous 

 membrane covering the nasal septum 

 can be similarly prepared as a whole 

 mount it is likely that the method may 

 be of service in the study of other sheets 

 of epithelial cells. 



3. Sheets of epidermis for chemical 

 analysis. Until very recently the 

 handicap experienced in chemical analy- 

 sis of the skin has been the difficulty of 

 separating epidermis and dermis by 

 themselves for analysis . All data on the 

 epidermis are of doubtful value because 

 variable amounts of dermis have been 

 included. The method of obtaining 

 pure epidermis by dilute acetic acid 

 separation is unsatisfactory for numer- 

 ous reasons. Baumberger, J. P., Sunt- 

 zeff, V. and Cowdry, E. V., J. Nat. 

 Cancer Inst., 1942, 2, 413-424 have 

 discovered that dilute alkali will serve 

 as well as dilute acetic but this also 

 is objectionable from the chemical 

 point of view. They therefore advance 

 a heat method. Place excised skin with 

 dermis down on warm plate such as is 

 used for mounting paraffin sections. 

 Apply temperature of 50°C. for 2 min. 

 which loosens the epidermis so that it 

 can be easily pushed off with a blunt 

 instrument. Separation is more diffi- 

 cult when temperature is over 51 °C. 

 Epidermises removed in this way for a 

 time continue to consume oxygen and 



