232 METHODS AND FORMULAS F 6800.0000-F 7000.0040 



6800.0000 Lenoir 1926 19076, 38 :720 



formula: water 250, chromic acid 2.5, potassium iodide 2.5 



6S00.0010 Chromic- {other inorganic salts)-acetic 



6800.0010 Semmens 1939a CSl9—auct. Microscope, Z -A 



formula: water 249, chromic acid 2, ammonium uranate 0.65, acetic acid 1 

 note: The ammonium uranate is prepared as follows. Wash 10 uranium trioxide by- 

 stirring and decantation with 20 5% hydrochloric acid. Dissolve residue in 20 cone, 

 hydrochloric acid, filter and add ammonia to filtrate until precipitation complete. 

 Wash and dry ppt. 



6800.0010 Semmens 1939b Flemming-uranic — auct. Microscope, 3:5 



formula: water 238, chromic acid 1.9, sodium uranate 2.5, acetic acid 12.5 

 note: The sodium uranate is prepared as the ammonium uranate of "a," with the 

 substitution of N sodium hydroxide for ammonia. 



6800.0010 Semmens 1939c Benda-uranic — auct. Microscope, 3:5 



formula: water 250, chromic acid 1.5, sodium uranate 2, acetic acid 2.5 



6800-0030 Chro7nic- (other inorganic saUs)-formic 



6800.0030 Pianese test. 1904 Besson Besson 1904, 750 



formula: water 250, chromic acid 1, cobalt chloride 20, formic acid 0.3 



F 7000 BICHROMATE WITHOUT OTHER PRIMARY FIXATIVE AGENTS 



7000.0000 Dichromate Alone 



Bichromate alone is an adequate general-purpose bulk fixative when it is desired to 

 preserve large masses of material. The cytological and histological pictures obtained from 

 this fixative, however, are not so good as those obtained with other classes. 



7000.0000 Cajal 1890 23632, 7 :332 



formula: water 250, potassium dichromate 9 



7000.0000 Cole 1884 Cole 1884b, 21 



formula: water 185, 95% ale. 65, potassium dichromate 3.6, sodium sulfate 2 



7000.0000 Gerlach 1872 test. 1928 Gatenby and Cowdry 



Gatenby and Cowdry 212 

 formula: water 250, ammonium bichromate 5 



7000.0000 Golgi 1903 Golgi 1903, 1:163 



formula: water 250, potassium dichromate 5 



7000.0000 Hamilton 1878 11025, 12:254 



formula: 25% ale. 250, potassium dichromate 4.8, potassium sulfate 2.4 



7000.0000 Miiller 1859 Miiller's Fluid— compl. script. 22302, 10 :80 



formula: water 250, potassium bichromate 6.25, potassium sulfate 2.5 



7000.0010 Dichromate-acetic 



7000.0010 Tellyesniczky 1898 1780, 52 :242 



formula: water 250, potassium dichromate 7.5, acetic acid 12.5 



note: This is the " Tellyesniczky 's Fluid" of most authors, but see also F 0000.1010 and 

 F 3500.0010. 



7000.0040 Dichromate-nitric 



7000.0040 Benda test. 1900 Pollack Pollack 1900, 30 



REAGENTS REQUIRED: A. 10% nitric acid; B. 1% potassium dichromate 

 method: [fresh tissue] — > A 24 hrs. — > B 14 days 



7000.1000 Dichromate-formaldehyde 



The apparently irrational dichromate-formaldehyde mixtures, including the next class 

 with the addition of acetic acid, are excellent fixatives for heavily yolked material. They 

 exercise less hardening effect, and render this material less brittle, than any other group. 

 Though the majority have been proposed for the purpose of cytoplasmic fixation only, they 

 are to be widely recommended in embryological practice. These mixtures must be prepared 



