ALTMANN'S FLUID 



ALUMINUM CHLORIDE CARMINE 



Altmann's Fluid. Equal parts of 5% aq. 

 potassium bichromate and 2% aq. osmic 

 acid. Employed in his method as well 

 as for staining with Copper Chrome 

 Hematoxylin. It gives good surface 

 fixation but penetrates very badly. 



Altmann's Method of anilin fuchsin and pic- 

 ric acid for mitochondria. Fix small 

 pieces not more than 2 mm. in diameter 

 24 hrs. in Altmann's Fluid. Wash for 



1 hr. dehydrate, clear imbed in paraffin 

 and cut sections i/i. Pass down to 

 water. Stain in anilin fuchsin (20% 

 acid fuchsin in anilin water) 6 min. 

 Blot with filter paper. Differentiate 

 and counter stain by flooding the sec- 

 tions with 1 part sat. ale. picric acid and 



2 parts aq. dest. Rinse rapidly in 95% 

 ale, dehydrate in abs. ale, clear in 

 xylol and mount in balsam. The mito- 

 chondria are stained crimson against a 

 bright j^ellow background. Altmann's 

 magnificent original plates should be 

 examined (Altmann, R., Die Elementar- 

 organismen und ihre Beziehungen zu den 

 Zellen. Leipzig: Veit Co., 1894, 160 

 pp.). If these are not available see 

 Meves, F., Arch. f. mikr. Anat., 1913, 

 82, (2), 215-260. 



Altmann-Gersh frozen-dehydration method 

 (Gersh, I., Anat. Rec, 1932, 53, 309- 

 337). — Account written by Dr. Gordon 

 H. Scott, Dept. of Anatomy, Wayne 

 University School of Medicine, De- 

 troit, Mich. This method has proved 

 to be of much value in the preparation 

 of tissues for microchemical proce- 

 dures. It has also been used as a pre- 

 liminary treatment for tissues destined 

 for examination by the electron micro- 

 scope (Wyckoff, R. W. G., Science, 

 1946, 104, 21-26). Tissues are frozen 

 in liquid nitrogen or in liquid oxygen 

 and dehydrated in vacuo at low tem- 

 peratures. The tissue sample remains 

 frozen at such a temperature that little 

 or no chemical change can take place. 

 It is believed that the only significant 

 revision in cellular organization takes 

 place during the freezing process. This 

 is occasioned by possible shifts in pro- 

 teins, etc., during ice crystal formation. 

 Some users of the method believe that it 

 is possible to freeze small tissue samples 

 at speeds which will actually prevent 

 ice crystal formations. Efforts in this 

 direction have been made by freezing 

 in cooled iso-pentane (technical) 

 (Hoerr, N. L., Anat. Rec, 1936, 65, 293- 

 317; Simpson, W. L., Ibid., 1941, 80, 

 173-189). 



For many reasons it has been found 

 desirable to dehydrate at lower tem- 

 peratures than were first thought neces- 

 sary. Now the standard procedure is 



to dehydrate in vacuo from 40-65°C. 

 Apparatus of special design has been 

 constructed a number of times to meet 

 various needs. In general the prin- 

 ciples are the same. What is needed 

 is a vacuum system with high pumping 

 speed and with provision for keeping 

 the frozen tissue at constant tempera- 

 ture. Several of these have been de- 

 scribed, each with its adaptation to the 

 needs of the case. 



For general use in histochemistry the 

 device described by Packer and Scott 

 (J. Tech. Methods, 1942, 22, 85-96) and 

 by Hoerr and Scott (Medical Physics, 

 Otto Glasser, 1944, Year Book Pub- 

 lishers) is both easy to operate and re- 

 liable. It has the distinct advantage 

 that tissues can be infiltrated with 

 paraffinjwithout^exposure to air. This 

 apparatus can also be used for the 

 preparation of tissues for electron 

 microscopy. For this use only the de- 

 hydration device described by Wyckoff 

 is probably more suitable. 



Recently developed equipment will 

 permit drying frozen tissues in 5 hours. 

 (Stowell, R. E., Stain Techn. 1951, in 

 press) 



Alum. The alums are double salts of sul- 

 phuric acid. Aluminum potassium sul- 

 phate, or potassium alum, unless other- 

 wise stated is the one used in making up 

 hematoxylin solutions. Aluminum am- 

 monium sulphate, or ammonia alum, 

 should not be used as a substitute unless 

 called for. Ammono-ferric sulphate, or 

 iron alum is used as a mordant and differ- 

 entiator in the iron hematoxylin tech- 

 nique and for other purposes. The 

 crystals are of a pale violet color. Their 

 surfaces oxidize readily and become use- 

 less. The surface should be scraped off. 

 Only the violet crystals are of any use. 



Alum-Carmine (Grenacher). Boil 1-5% aq. 

 ammonia alum with 0.5-1% powdered 

 carmine. Cool and filter. Does not 

 penetrate very well and hence is not 

 suitable for staining large objects in 

 bulk. But it is useful and does not 

 overstain (Lee, p. 140). 



Alum-Cochineal, see Cochineal. 



Alum Hematoxylin. Many hematoxylin so- 

 lutions contain alum, see Delafield's, 

 Ehrlich's, Harris', Mayer's. 



Aluminium Chloride Carmine (Mayer). 

 Dissolve 1 gm. carminic acid and 3 gm. 

 aluminium chloride in 200 cc. aq. dest. 

 Add an antiseptic as formalin or 0.1% 

 salicylic acid. Employ in same way as 

 carmalum. Gives blue violet color. 

 Very penetrating but not so specific for 

 chromatin as carmalum (Lee, p. 142). 



