GOLGI APPARATUS 



111 



GOLGI APPARATUS 



In 1902 Kopsch showed that the same 

 material can be blackened by prolonged 

 treatment with 2% osmic acid. On this 

 affinity for both silver and osmium all 

 the modern methods for revealing the 

 Golgi apparatus are based. Few cy to- 

 logical reactions are more fickle and 

 inconstant, but, when after many at- 

 tempts the technique is successful, 

 convincing and very beautiful prepara- 

 tions result. Unlike the mitochondria, 

 the Golgi apparatus cannot be studied 

 unstained or supravitally colored in the 

 living cell with any degree of satisfaction 

 except perhaps in some plants (Guil- 

 liermond, A., Arch. d'Anat. Micro.. 

 1927, 23, 1-98; see particularly colored 

 plate 1). There is some evidence how- 

 ever that droplets of material stainable 

 with neutral red may be associated 

 topographically with the Golgi apparatus 

 (Cowdry, E. V. and Scott, G. H., Arch. 

 Inst. Pasteur de Tunis, 1928, 233-252; 

 Covell, W. P. and Scott, G. H., Anat. 

 Rec, 1928,38,377-398). 



With both silver and osmium methods 

 considerable experimentation is neces- 

 sary in order to obtain the best results. 

 The factors to be varied are principally 

 the composition of the fixative and 

 impregnating substance and the time 

 during which they are allowed to act. 

 During impregnation it is always ad- 

 visable to keep the tissues in the dark 

 and instructions as to temperature 

 requirements should be carefully fol- 

 lowed. When either the silver nitrate 

 or osmic acid becomes blackened it 

 should be renewed. It is important for 

 the beginner to start with the most 

 favorable material. The spinal ganglion 

 cells of young mammals such as the 

 rabbit are perhaps the best for this 

 purpose. The acinous cells of the pan- 

 creas are also recommended but are 

 somewhat more difficult to handle. All 

 of the methods of impregnation outlined 

 below frequently bring to light the 

 mitochondria also. 



1. Cajal's uranium nitrate silver 

 method, Carleton, H. M., J. Roy. Micr. 

 Soc, 1919, 321-328. This is one of 

 many methods devised by Cajal. It is 

 recommended for embryos and young 

 animals. Fix in uranium nitrate, 1 

 gm. ; formalin, 15 cc. ; and aq. dest., 100 

 cc, 8-24 hrs. Wash quickly in aq. 

 dest. 1.5% aq. silver nitrate 24-48 hrs. 

 Rinse in aq. dest. Hydroquinone,2gm. ; 

 formalin, 6 cc; aq. dest., 100 cc; an- 

 hydrous sodium sulphite, 0.15 gm., 12 

 hrs. Wash in aq. dest., dehydrate 

 quickly, clear, imbed, and section. 



2. Da Fa7w's cobalt nitrate silver 

 method, Da Fano, C., J. Roy. Micr. Soc, 

 1920, 157-161 . Here the uranium nitrate 



is replaced by cobalt nitrate. In other 

 respects the technique is similar. Da 

 Fano has, however, so carefully at- 

 tempted to control troublesome experi- 

 mental conditions that the various steps 

 are given in detail. Fix in cobalt nitrate, 



1 gm.; aq. dest., 100 cc; formalin, 15 

 cc; 6-8 hrs. The formalin need not be 

 neutralized unless it is strongly acid. 

 In the case of embryos and delicate tis- 

 sues, when shrinkage is to be feared, 

 reduce the formalin to as little as 6 cc. 

 With cartilage and small pieces less than 

 3 mm. thick, like the organs of mice, 

 shorten the time of fi.xation to 3 to 4 hrs. 

 Hollow organs, such as the stomach and 

 intestine, had better be placed in the 

 fixing fluid for 1 hr. and then be cut into 

 pieces of convenient size and shape. 

 For the spinal cord, cerebellum and 

 cerebrum of adults, 8-10 hrs. is recom- 

 mended, but fixation should never ex- 

 ceed 24 hrs. In the case of the testicle, 

 he advises injection of the fixative 

 through the aorta and then immersion 

 in it. Wash quickly in aq. dest. and 

 impregnate in 1.5% aq. silver nitrate 

 24-48 hrs. The concentration of silver 

 nitrate should be reduced to 1% for very 

 small fragments easily permeable, and 

 be increased to 2% for tissues containing 

 much fat and for the spinal cord. Im- 

 pregnation is effected at room tempera- 

 ture in a majority of cases. When 

 difficulty is experienced in impregnation 

 the use of an incubator at 36° to 37 °C. 

 is advised. Wash rapidly in aq. dest. 

 and cut down the tissues again to a 

 thickness of 2 mm. or less. Reduce in 

 Cajal's hydroquinone mixture, above 

 mentioned, 12-24 hrs. Wash in aq. 

 dest. 5 hr. Cut with a freezing micro- 

 tome or imbed in paraffin. The Golgi 

 apparatus should be colored dark 

 brown or black against a yellow back- 

 ground. The preparations may be made 

 more permanent by gold toning. Pass 

 to water. Then 0.1-0.2% gold chloride, 



2 hrs. Counterstaiu with Alum Car- 

 mine, dehydrate, clear and mount. 



3. Kopsch's method, Kopsch, F., Sitz.- 

 Ber. d. K. Preuss. Akad. d. wiss. Math. 

 KL, 1902, 40, 929-935. Immersion of 

 small pieces of tissues in 2% aq. osmic 

 acid for 8-16 days often brings to light 

 the Golgi apparatus but there is con- 

 siderable shrinkage and the tissues be- 

 come rather brittle. 



4. Sjovall's modification, Sjovall, E., 

 Anat. Hefte, 1906, 30, 261-391. Fix in 

 10% formalin, 8 hrs. Wash in aq. dest. 

 2% osmic acid at 35°C., 2 days. De- 

 hydrate, clear, imbed. 



5. Hirschler's modification, Hirschler, 

 J. Arch. f. mikr. Anat., 1918, 89, 1-58. 

 Fix in sat. aq. mercuric chloride, 10 



