E11.1-E21 EMBEDDING MEDIA 045 



11.1 Romeis 1948 Romeis 1948, 109 



formula: water 75, phenol 0.75, golatin 25 

 method: [objtMit washed free of fixative) -* 50% enibeddinf; jiiediuin, 21 hrs., 37°C. —> 



embedding ni(>diurn, 30 mins. -^ [set as blo(;k; evaporate till surface tacky]—* 10% 



formaldehyde, 1-2 days —* [frozen sections] 

 note: This is a synthesis by Romeis {loc. cit.) of the methods of Gaskell 1912 (11431, 



20:17), and Graff 1916 (14674, 63:1482). 



11.1 Salkind 1916 6630,79:16 



REAGENTS REQUIRED: A. cherry gum 25, water 50, lead subacetate solution (N.F. VI) 25, 

 acetic acid 1.5; B. ammonia 



preparation: Dissolve gum in water. Mix lead subacetate solution and acetic acid and 

 add to filtrate. 



method: [water] — > A, till impregnated — > [paper boat] — > vapor of B, till hard enough 

 to cut 



note: The original method, and also the citation in Gatenby and Cowdry 1937, 108 

 call for "Extract of Saturne" (sic). Gray 1816 {Treatise on Pharmacology, 318) refers to 

 a solutionj'obtained by boiling litharge with distilled vinegar as "Goulard's Extract 

 of Saturn." The Merck Index, 1940, 315 refers to the NF solution given above as 

 "Goulard's Extract." Whether or not the strength of Salkind's solution was that of 

 the NF does not appear to be ascertainable. 



11.1 Samuel 1944 11025,78:173 



reagents required: A. 0.65% agar in 2% formaldehyde; B. 1.3% agar in 2% formalde- 

 hyde 

 method: [small objects] -^ film of B cast on slide -^ A, around but not over object — > 

 film of B over object -* paraffin 



11.1 Tobias 1936 Tobias 1936, 74 



formula: water 60, gum arabic 40, phenol 0.5 



11.1 Webb 1890 11360, 113 



formula: water 100, phenol 2.5, dextrin q.s. to give a thick syrup 



11.1 Zwemer 1933 763, 57:41 



reagents required: A. b% gelatin; B. 10% gelatin; C. 4% formaldehyde 

 method: [formaldehyde fixed tissues]-^ A, 24 hrs., 37.5°C. ^ B, 12 hrs. 37.5°C. -> 

 [cast block] -^ C, till required — > [sections by freezing technique] 



E 20 Embedding Media Not Miscible with Water 



Before material can l)e embedded in these media for cutting, it must l^e subjected to 

 whatever treatment is specified in Chapters 12 through 14. In general, liowever, this 

 treatment consists of the removal of water from the specimen with a dehydrating agent 

 and the substitution for the dehj'drating agent of a solvent whicli is itself miscible with 

 the embedding material. Three main types of media are distinguished in the present 

 chapter. First (E 21.1) come the numerous wax media which have been suggested to re- 

 place straight paraffin in the production of sections; second, nitrocellulose media, more 

 commonly referied to as " ceUoidin," in which there are few media but a considerable 

 number of methods, j^articularly for double embedding; third (E 23) resinous materials 

 which are intended for the inclusion of matter from which sections are to be ground, as 

 indicated in Chapter 10, rather than cut. 



21 WAX MEDIA 



The original method of cutting sections eml)ed(led in wax, which is described in detail 

 in Chapter 12, was to dehydrate the specimen with alcoliol, to remove the alcoliol either 

 with an essential oil or a hydrocarbon, and then to embed the material in straight paraf- 

 fin. This technique has been modified both tlirough the introduction of substitutes for, 

 or adjuvants to, paraffin, and by the introduction of other solvents. In the section which 



