AUTORADIOGRAPHY 



337 



is difficult. There are possibilities of radioisotope loss during any pre- 

 liminary histological processing and also by solution into the hquid 

 emulsion. 



Recommended Usage. Coating autoradiograms have proved satisfac- 

 tory for cytological studies with hones, teeth, and soft tissues. 



Typical Method. This procedure was first described by Belanger and 

 Leblond (29) and represents perhaps the first successful method in which 



£^=Emu/s/on 



Fig. 7-3. Coating method. The gel is maintained at 37°C in a beaker, and the slides 

 are warmed (a) ; drops of the fluid emulsion are applied to specimen on marked slide 

 (b); the drops are spread evenly (c); and the slide is tilted to give even distribution (d). 

 [Courtesi/ of Patrick J. Fitzgerald, Eva Simmel, Jerry Weinstein, and Cynthia Martin, 

 Radioautography: Theory, Technic, and Applications, Lab. Invest., 2: 181-222 (1953), 

 Paul B. Hoeber, Inc., publisher.] 



intimate contact was accomplished between specimen and emulsion. 

 The following procedure was presented by Gross et al. (5) and is illus- 

 trated in Fig. 7-3 [from Fitzgerald et al. (10)]: 



1. Stained or unstained histological sections are coated with celloidin 

 by dipping twice in a 1 per cent ether alcohol solution. 



2. Ansco autoradiographic emulsion A is used, or Eastman Kodak 

 medium lantern-slide emulsion, which is obtained by soaking the glass 

 plates for 10 min in distilled water at 19°C and scraping. 



3. The emulsion is placed in a beaker and maintained at 37°C for 

 15 min. Improved resolution is obtained by diluting 1 ml of lantern- 



