48 



drain from the other end of the slide, repeating the operation two or 

 three times if necessary. If the sections are well pressed down and 

 the clarifier thoroughly absorbed the sections will stick to the slide 

 under most rough manipulation. If, however, it is found that the 

 sections tend to float off of the slide in the process of staining, their 

 adhesion may be insured by using albuminized slides, or removing 

 the slides from the alcohol ( 144) and again treating with ether- 

 alcohol. 



Sections cut in alcohol may require more ether-alcohol. 



136. Celloidin Sections with Removal of the Celloidin. In 

 the above method, the celloidin is used in fastening the section to 

 the slide. As celloidin stains heavily with most basic stains, it is 

 sometimes desirable to have it removed as is paraffin. In most such 

 cases, the difficulty may be avoided by employing paraffin as the 

 imbedding method; where this is not possible, imbed in celloidin as 

 usual but harden and cut in alcohol. Use 67% alcohol on the 

 microtome knife, handle the sections with tissue paper as usual 

 ( 70), but before transferring them to slide previously prepared 

 with albumen fixative ( 138), let as much of the alcohol evaporate 

 as is possible without the sections drying. They should also be free 

 from wrinkles. Press the sections down well, remove the tissue 

 paper and place the slide in 95% alcohol which will harden the 

 albumen fixative cement. The celloidin may be removed now or just 

 before clearing by means of ether-alcohol, absolute alcohol, or clove 

 oil. 



137. Free-hand Sections and such made with the freezing 

 microtome may be fastened to the slide if desired by albumin fixa- 

 tive or M% celloidin or both. If the first is used, the sections should 

 be transferred to the albuminized slide from water which should be 

 largely absorbed and the sections pressed down by tissue paper. If 

 the latter, press sections to a clean slide with paper, pour on 95% 

 alcohol, dip cautiously into %% celloidin, drain and place slide in 

 95% alcohol. 



138. 2. Paraffin Sections are most conveniently fastened 

 to the slide by albumen fixative and spreading with water, as fol- 

 lows: Place upon the slide a small drop of Mayer's albumin fixa- 

 tive* and with a (clean) finger tip spread it into a thin even film. 

 Place upon the albuminized surface enough distilled water to float 



M*ayer's Albumen fixattie. White of egg, 50 c. c. ; glycerin, 50 c. c. ; salicylate 

 of soda, 1 gram. Shake them thoroughly and filter. 



