GOLGI, METHOD 



147 



GOMORI'S METHODS 



sential to determine the age of the 

 animal at which the cell or fiber selected 

 for study is reaching maturity. For 

 example, if new born kittens are chosen, 

 and the area striata is the object of 

 study, the best impregnations of enter- 

 ing fibers are obtained at 12 to 15 days 

 after birth ; of short axon cells, at 18 to 21 

 days; and of pyramids at 21 to 24 days. 

 Cut slices of brains 3-4 mm. in thick- 

 ness by quick cuts of a sharp scissors. 

 Fix in: potassium bichromate, 10 gm.; 

 osmic acid, 1 gm.; aq. dest., 330 cc. 

 Time of fixation must be determined 

 for each part of the CNS studied. In 

 general the older the animal, the longer 

 it is. After fixation, blot blocks of 

 tissue on filter paper and transfer to a 

 bottle containing f% aq. silver nitrate. 

 After 24 hrs. the reaction is complete. 

 Imbed in celloidin. Subsequent treat- 

 ment is very important. Place block in 

 95% ale. for about 5 min., remove and 

 blot dry. Place block on paraffin disc 

 mounted on a block holder in the orienta- 

 tion desired for cutting. Using a hot 

 teasing needle, melt paraffin around the 

 block so as to fasten block to paraffin. 

 Be sure that melted paraffin does not 

 creep up on the block. Use knife at 45° 

 angle to the block. Cut serially 80-100ai. 

 Place each section as cut in order in 95% 

 ale. using Petri dishes. Be sure not to 

 miss first and last section of the block 

 for these are often more valuable than 

 the entire remainder of the block. 

 Using a spatula, transfer to another 95% 

 ale. after 5 min. After another 5 min. 

 transfer to oil of cloves, arranging in 

 serial order, by placing each section as 

 it enters oil of cloves near the edge of 

 the Petri dish so that it adheres to the 

 edge. When all sections are transferred 

 the group will be placed around the 

 circumference of the Petri dish. As the 

 sections start to retract from the edge, 

 begin to arrange them in the usual order 

 for serial sections. After clearing (clove 

 oil 5 to 10 min.) transfer in serial order 

 to slides. Blot off excess of clove oil 

 and apply xylol, blot off xylol similarly 

 and apply a thin layer of Damar, using 

 the drop method. Let the slide dry on 

 an even surface adding more Damar as 

 necessary to keep sections protected. 

 Golgi, Method (Porter, R. W. and Daven- 

 port, H. A., Anat. Rec, 1949, 103, 583). 

 Radical departure from prior methods 

 because silver impregnation precedes 

 the potassium bichromate solution. 

 Fix 48 hours at 25°C. in 90 cc. 0.5 aq. 

 AgNOj, 10 cc. formalin, 0.5 cc. Pyridine. 

 Mix in order given, disregarding slight 

 turbidity. Colorimetric test of fixing 

 solution with bromcresol purple should 

 show 5.5 to 6.0. Fixation can be done 



by perfusion, or only by immersion. 

 Cut slices to thickness of 0.5 to 1.0 cm. 

 After fixation rinse blocks with dis- 

 tilled water and place in 2.5% (aq) po- 

 tassium bichromate to which 1 cc. of 

 1% osmic acid is added for each 100 cc. 

 Leave there 3 to 5 days. Dehydrate 

 quickly through alcohols and xylol to 

 soft paraffin. Sections should be cut 

 50 to 100 microns thick. 

 Gomori's Methods For Reticulum and Acid 

 Phosphatase. 



1. Silver impregnation of reticulum 

 (Gomori, G., Am. J. Path., 1947, 13, 

 993-1001). Treat deparaffinized sec- 

 tions of formalin fixed material with 

 0.5-1% aq. potassium permanganate. 

 1-2 min. Rinse in tap water and 

 decolorize in 1-3% aq. potassium meta- 

 bisulphite, 1 min. Wash for several 

 minutes in running tap water. 2% 

 aq. iron ammonium sulphate (violet 

 crystals), 1 min. Wash in tap water 

 few minutes and then pass through 2 

 changes aq. dest. Impregnate for 1 

 min. in following solution: To 10% 

 aq. silver nitrate add g to J of its volume 

 of 10% aq. potassium hydroxide. While 

 shaking add strong ammonia drop by 

 drop until ppt. is completely dissolved. 

 Add carefully silver solution drop by 

 drop as long as resulting ppt. easily 

 disappears on shaking. Finally add 

 equal vol. aq. dest. Can be kept 2 days 

 in stoppered bottle. Rinse in aq. dest., 

 5-10 sec. Reduce in commercial forma- 

 lin diluted 5-10 times with tap water. 

 Wash under tap few min. Tone in 

 0.1-0.2% aq. gold chloride, 10 min. 

 1-3% aq. potassium metasulphite for 1 

 min. Fix in 1-2% aq. sodium thio- 

 sulphate (hyposulphite) for 1 min. 

 Wash under tap, dehydrate, clear 

 and mount. Reticulum black. Note 

 author's figures of sarcomata (Revisde 

 by G. Gomori May 7, 1946). 



2. For Acid phosphatase — Written 

 by G. Gomori (University of Chicago. 

 May 7, 1950— see Stain Techn., 1950, 

 25, 81. 



1. Fix thin slices of tissues in ice cold 

 acetone for 24 hours. 



2. Change acetone at room tempera- 

 ture twice for the next 24 hours. 



3. Two changes of benzene, 45 min. 

 each. 



4. Embed in paraffin (not abo\'e 56°C. 

 and preferably below), 2 changes, 30 to 

 45 min. each. 



5. Cut sections. Float them on luke- 

 warm (30°C.) water. 



6. Carry sections through xylene and 

 2 alcohols to dist. water. 



7. Incubate in the following solutions 



