324 GOLGI BODIES, ETC. 



liquid decanted, and the precipitate is washed ten or twelve times in 

 about a litre of distilled water ; 50 c.c. of water are then added to it, 

 and then ammonia drop by drop until the precipitate is dissolved. 

 This stock is brought up to 150 c.c. by adding distilled water, and keeps 

 for months.) 



Impregnation is carried out in three dishes, the first containing 10, 

 the second 15, the third 20 drops of the above solution in 10 c.c. of 

 distilled water. The objects are left in each strength until the silver 

 begins to precipitate, making the liquid turbulent. In the last dish 

 there should be no precipitation. 



Wash in distilled water. Transfer to gold chloride. Fix in sod. 

 hyposulphite 1 per cent, for a short time only. Wash in distilled water, 

 upgrade and mount in balsam. In our hands results no better than 

 Weigl. 



730a. Combined Golgi Apparatus and Fat Stain (Gatenby, 

 Biological Technique, 1937). A successful method is the combined 

 Aoyama (or Da Fano) and Sudan IV. You prepare either smears 

 or frozen sections by, preferably, the Aoyama method. The 

 piece of tissue cannot be imbedded in wax as the upgrading in 

 alcohol to xylol removes the fat, so frozen sections must be cut, 

 and the thinner the better, or the material may be teased. After 

 the Aoyama smear, or the block of tissue has been brought into 

 reducing fluid as described in § 725, it should be washed in water. 

 The smear goes immediately on to the fat stain, whereas the 

 block of tissue is sectioned, and then stained in Sudan IV, or a 

 small piece is first stained in Sudan IV and then teased up in 

 glycerin and water (1:1). In both cases the mountant is Berlese 

 (§ 1188) and not glycerin, glycerin jelly, or Farrants, the reason 

 being that glycerin attacks the silver. 



Exactly the same can be done after the Weigl or Kolatchew 

 methods. You stain in Sudan IV and mount in Farrants, glycerin 

 or glycerin jelly (§691). 



In both the silver nitrate and the osmic method the Goljji 

 apparatus is black, and fat is red, but in some osmic preparations 

 the colour of the fat is brownish red rather than the bright red 

 of the formalin silver preparations. 



731. Plan for Material Fixed in One, Two or Three Lots. 

 A. (1) Fix in Cajal or Aoyama 



(2) Continue on (2a) Post - chrome (2b) Wash out, 

 with Golgi apparatus in 3 per cent, to cut frozen sections 

 method. 5 per cent. KgCrjO^ or tease, for fat 



I for three days. stains, mount in 



(3) Counterstain \ Berlese. etc. Also 

 in Mann's methyl Wash out under chlorocarmme. 

 blue eosin. tap overnight. 



(3a) Stain in iron 

 lijematoxylin or acid 

 fuchsin for mito- 

 chondria. 



