AMYL ALCOHOL 



11 



AMYLOID 



Amyl Alcohol. Merck lists 3, commercial, 

 normal and tertiary. It mixes with 

 95% alcohol and with xylol. HoUande 

 (A. C, C. rend Soc. de Biol., 1918, 81, 

 223-225) was the first to recommend 

 amyl alcohol as a substitute for absolute 

 alcohol in the dehydration of specimens 

 sta,ined by the Romanovsky and Giemsa 

 techniques. 



Amyl Nitrite. McClung (p. 620) says that 

 this may serve as a dilator of peripheral 

 capillaries when a complete injection 

 of small blood vessels is required. Add 

 it to the ether at time of anesthetization. 



Amylase, micromethod for (Pickford, G. E. 

 and Dorris, F., Science, 1934, 80, 317- 

 319). This was later used with marked 

 success by Dorris (F., J. Exp. Zool., 

 1935, 70, 491-527) in a study of relation 

 between enzyme production and histo- 

 logical development of gut of ambly- 

 stoma. An extract is made, adjusted 

 to proper pH, applied to slides coated 

 with a starch-agar solution and incu- 

 bated. The slides are then washed, the 

 coating fixed in formalin and colored 

 with dilute iodine solution. Sites of 

 amylase activity are clear or pink stain- 

 ing spots. For necessary details, see 

 author's description, van Genderen 

 andEngel (H.andC., Enzymologia, 1938, 

 5, 71-80) localized this enzyme by 

 analysis of horizontal sections through 

 the intestinal wall. It was found that it 

 is present in rabbits in maximum amounts 

 in Brunner's glands. Holtfir and Dogle 

 (C. R. Lab. Carlsberg, S6r. Chim., 1938, 

 22, 219-225) observed that in amebae it 

 is concentrated in association with the 

 mitochondria which they assume to be 

 carriers of amylase. See Barnes, J. M., 

 Brit. J. Exp. Path., 1940, 21, 264-275 

 for identification of amylase in lympho- 

 cytes and polymorphonuclear leuco- 

 cytes . 



Salivary amylase digests glycogen in 

 sections, but does not alter mucus, 

 cartilage matrix and other mucins which 

 give similar histochemical reactions. 

 Lillie, R. D., Stain Tech., 1947, 22, 67- 

 70, recommends a commercial prepara- 

 tion of diastase for this purpose, but 

 Dempsey and Wislocki prefer saliva, 

 since the commercial preparations ap- 

 parently contain traces of mucinase 

 which attacks mucus, cartilage and 

 mast cell granules. 



Amyloid (G. arnylon, starch and eidos, re- 

 semblance), a substance which accumu- 

 lates in pathological conditions in the 

 tissue fluids between cells particularly 

 in chronic infections. Methods for its 

 detection are fully described by Mallory 

 and Parker (McClung, pp. 417-419). 

 From nimaerous tests the following are 

 selected : 



1. Iodine and sulphuric acid: Stain 

 section lightly with Lugol's iodine. 

 Place in 1-5% aq. or cone, sulphuric or 

 hydrochloric acid. Color of amyloid 

 changes quickly from red through 

 violet to blue or it may become deep 

 brown . 



2. Methyl-violet: Treat frozen sections 

 of fresh, formalin or alcohol fixed tissue 

 with 1% aq. methyl violet, 3-5 min. 

 Wash in 1% aq. acetic acid, and remove 

 acid by washing carefully in water. 

 Examine in glycerin or water. Amyloid 

 is violet and tissue blue. Colors will be 

 retained longer if sections are mounted 

 in Levulose Syrup. 



3. Iodine green: Fresh or hardened 

 sections are stained 24 hrs. in 0.3% 

 aq. iodine green. Wash in water and 

 examine in water or glycerin. Amyloid 

 is stained violet red and tissue, green. 



4. Mayer's stain: Transfer paraffin 

 sections immediately after cutting to 

 0.5% aq. methyl violet or gentian violet 

 at 40°C. for 5-10 min. Rinse in water 

 and differentiate in 1% aq. acetic acid 

 for 10-15 min. Wash thoroughly in wa- 

 ter. Change to ^ sat. aq. alum and wash 

 it off in water. Place section on slide and 

 let water evaporate. Remove paraffin, 

 clear in xylol and mount in balsam. 

 Crystal violet and iodine green can be 

 employed in the same way. 



A Congo red test has been described 

 (Taran, A., J. Lab. & Clin. Med., 1936- 

 37, 22, 975-977) and a polysaccharide 

 has been isolated from amyloid bearing 

 tissues which closely resembles chon- 

 droitin-sulphuric acid obtained from 

 infantile cartilage (Hass, G., Arch. 

 Path., 1942, 34, 92-105). 



As pointed out by Highman, B., Arch. 

 Path., 1946, 41, 559-562 the staining 

 methods for amyloid are in general 

 satisfactory when employed by skilled 

 workers. However, when stained sec- 

 tions are mounted in glycerin Apathy's 

 syrup, or some such medium, they tend 

 to fade quickly, or the stain diffuses out 

 into the surrounding tissue, or mount- 

 ing medium, and the nuclei are seldom 

 sharply colored. Highman therefore 

 recommends staining of deparaffinized 

 sections of formalin fixed tissues in iron 

 hematoxylin 5 min., washing in water, 

 staining in 0.5% crystal violet or methyl 

 violet in 2.5% aq. acetic acid, washing 

 again in water and mounting in Lillie 's 

 Apdthy's syrup modified by addition 

 of 50 gm. potassium acetate or 10 gm. 

 sodium chloride to 100 cc. of syrup. 

 He also gives a technique for mounting 

 in clarite. 



See Mallory-Heidenhain rapid one 

 step stain. 



