CH. VII] 



PARAFFIN SECTIONING 



hasten the solution of the paraffin by moving the slide in the solvent. In this way 

 it may be dissolved in 5 to 10 minutes, or even less. It will do no harm to leave 

 the slide in the benzin or xvlene over night. Two or three days even might not 

 do any harm, but it is usually better to proceed at once to the other operations. 



Fig. 160. Apparatus and regents with which the slide holders are used. With 

 this apparatus it is easy to prepare specimens in large numbers very expeditiously. 

 After the sections are fastened to the slide and placed in the holder, the slides need 

 not be touched during all the operations until they are finally ready to be mounted 

 in balsam. Each holder contains from 12 to 14 slides. (§ 277-300). The bottles 

 for the reagents are glass stoppered specimen or museum bottles. (Mix, four. Ap. 

 Micr. /SgS,p. 171.) Compare Fig. 14S. 



'i 292. Removing the Xylene or Benzin — From the xylene or benzin plunge 

 the slide bearing the sections into a jar of 95 ' ',, alcohol, and leave it for a few 

 minutes, or move it around in the alcohol for half a minute or so. 



\ 293. Staining the Sections with an Alcoholic Dye. — With an alcoholic 

 stain like hydrochloric acid carmine, remove the slide from the alcohol, and add 

 the stain directly after draining the slide, Do not allow the stain to become dry, 

 for that would injure the tissue. Wash away the stain with 67% alcohol, then 

 dehydrate with 95'',, alcohol, clear and mount in balsam as described below. 



\ 294. Staining with as Aqueous Dye. — Wash away the 95% alcohol from 

 the slide bearing the sections by plunging it into a jar of water and moving it 

 around a moment. Then add the stain to the sections with a pipette, or immerse 

 the slide in a jar of the stain, and allow the stain to act from 5 to 10 minutes. 

 Wash thoroughlv with water. 



\ 295. Staining with a General Dye — Counterstaining. — If it is desired to 

 give a general stain after the nuclear dye (? 294), carmine stained preparations 

 may be tinted with picric-alcohol for half a minute or more ( \ 333), and the hem- 

 atoxylin stained specimens with eosin ( {/ 321 ). It usually takes less than a minute 

 for this. Wash away the counterstain with water. 



