ADRENAL 



20 



ALCOHOL-FORMALIN 



Am. J. Anat., 1940, 67, 151-227 for keto- 

 steroid cortical hormone said bj^ Go- 

 mori, G., Proc. Soc. Exp. BioL & Med., 

 1942, 51, 133-134 not to be specific but 

 to indicate merely location of lipids 

 having keto or aldehyde groups. A 

 technique for microscopic study of 

 living grafts of adrenal cortex (Wil- 

 liams, O., Anat. Rec, 1945, 91, 307). 



Adrenalin, see Chromaffin Reaction. 



Aerosol, a detergent used in preparing bac- 

 teria for staining (Sineszko, S. F., 

 Science, 1942, 96, 589). 



Agar, as matrix for cutting plant material 

 with freezing microtome (Evenden, W. 

 and Schuster, C. E., Stain Techn., 

 1938, 13, 145-146). 



Age Changes are as manifold as life itself. 

 Some are detectable by structural 

 modifications while others can only be 

 measured by decrease in performance. 

 Many old tissues can easily be dis- 

 tinguished from new ones as for example 

 Bone. Some accumulate definite prod- 

 ucts with age like Lipofucsin. The age 

 of tissue and of cellular components, 

 that is the time they endure, can be 

 determined by attaching Tracer Sub- 

 stances to them so that their rates of 

 Replacement can be measured. With 

 the passage of time colloids age, become 

 less elastic and more granular. Old 

 Elastic Fibers can be distinguished from 

 young ones. Now that the ultra struc- 

 ture of CoHagenic Fibers has been re- 

 vealed by the electron microscope we 

 may hope for more accurate means of 

 estimating their condition in relation 

 to age. Numerous physical techniques, 

 including the Polarization Optical 

 Method, may well bring to light sig- 

 nificant age changes. Obviously many 

 methods of chemical analysis and of 

 enzyme activity provide data on the 

 modes of run down of vital activities. 



Agonal Changes are particularly difficult 

 to avoid in villi of small intestine. 

 They are evidenced by a ballooning of 

 the epithelial cap most marked when 

 absorption of ordinary food stuffs is 

 active. The ballooning phenomenon 

 can be produced in the living animal by 

 ligating arteries of supply or by em- 

 ploying fixatives which induce forcible 

 contraction of smooth muscle (Macklin, 

 C. C. and M. T., Chapter on Intestinal 

 Epithelium in Cowdry's Special Cy- 

 tology, N. Y., Hoeber, 1932, I, 235). 



Albert's Stain for Diphtheria Bacilli, which 

 see. 



Albumen-Glycerin for mounting paraffin 

 sections. Egg white 50 cc, glycerin 

 50 cc, sodium salicylate 1 gm. Shake 

 together and filter during several days. 

 See also Starch Paste and Masson's 

 Gelatin Glue. 



Alcohol. Unless indicated to the contrary 

 the word "alcohol" as employed in this 

 book refers to the ethyl variety. Alone 

 it is a good fixative preliminary to tests 

 for Amyloid, Copper, Fibrin, Glycogen, 

 Gold, Hemofuscin, Hyaline, Iron, Lead, 

 Palladium, Phosphatase, Potassium 

 and Thallium, which see. It is also 

 employed in the demonstration of Nissl 

 bodies by Gallocyanin, of mucus by 

 Mucicarmine, of proteins by the Ro- 

 mieu Reaction, etc. In combination 

 with other chemicals alcohol is also much 

 used as a fixative, see Alcohol Formalin, 

 Carnoy's Fluid and many others. 



Alcohol of 70% is a good preservative 

 and celloidin blocks can be stored in it. 

 Absolute alcohol is supposed to contain 

 not more than 1% by weight of water. 

 It is considered to be 100 per cent. A 

 very rough test for absolute alcohol is to 

 mix with it a few drops of turpentine. 

 If it becomes milky it contains too much 

 water. To make a lower per cent from a 

 higher one by dilution take the number 

 of cc. corresponding to the percentage 

 required and add aq. dest. to make in cc. 

 the percentage of the alcohol diluted. 

 Thus to make 30% from 70% take 30 cc. 

 of 70% and add aq. dest. to make 70 cc. 

 Alcohol is the best dehydrating agent 

 for tissues. It is sometimes not easy to 

 purchase absolute alcohol so that it must 

 be prepared. Take say 10 liters of 95% 

 alcohol, add 400 gms. freshly ignited 

 calcium oxide. Leave, with occasional 

 shaking, 24 hrs. until most of the water 

 is absorbed by the oxide. Pour off 

 fluid (leaving oxide at bottom of con- 

 tainer) and distill using appropriate 

 precautions. Keep the "absolute" as 

 nearly so as possible by using a tight 

 glass stopper for the bottle, or in place 

 of the stopper an absorption tube con- 

 taining calcium chloride so that any 

 water in entering air will be absorbed 

 and will not reach the alcohol. See 

 Dehydration, also Amyl, n-Butyl, Ter- 

 tiary Butyl, Isopropyl, n-Propyl and 

 Polyvinyl Alcohols. 



Alcohol-Formalin is a fixative containing 9 

 parts of absolute alcohol and 1 part of 

 formalin. Since it penetrates quickly 

 and deh3'dration can be commenced in 

 absolute alcohol immediately after fixa- 

 tion, skipping the lower grades of alco- 

 hol, permanent preparations can be 

 made within a few hours' tiine. For 

 routine purposes 3-6 hrs. fixation will 

 suffice but as a preliminary to Micro- 

 incineration 24 hrs. is recommended. 

 Alcohol-formalin is recommended for 

 Fibrin, Glycogen, Indigo-Carmine 

 stains aud Peroxidase. It is employed 

 with acetic acid in Bodian's Method 

 for nerve fibers. 



