47 



133. Handling the Sections. Sections may be carried on 

 through the staining and mounting processes either (a) not fastened 

 to the slide, as free or loose sections, or, (b) fastened to the slide, 

 which is of the greatest advantage and practically necessary in the 

 case of serial sections. The methods of fastening the sections to the 

 slide are different for celloidin and paraffin sections. 



134. Free sections. It is seldom necessary or advantageous 

 to carry paraffin sections through the processes of staining and 

 mounting not attached to slides because- of their delicacy and the 

 readiness with which they tear or fray. Celloidin sections may be 

 more conveniently carried on in this way. Loose sections may be 

 carried on in watchglasses or larger glass vessels if there are many 

 of them, the sections either being transferred from vessel to vessel 

 by means of forceps or a section lifter, or the fluid decanted, care 

 being taken not to pour off the sections, and the succeeding medium 

 added. Single sections may be best carried on upon the slide which 

 must be kept horizontal. When the fluid is to be changed, place a 

 brush or needle gently on one corner of the specimen and pour off 

 the liquid, if necessary first absorbing most of it by means of a 

 pipette; in this way the section may be retained on the slide. If 

 many sections, not in series, are to be treated in the same manner, 

 they may be placed in a perforated container, box or basket, 

 and handled as a unit by transferring the container from fluid to 

 fluid ( 144). When the final step is reached ( 159) the sec- 

 tions may be transferred to slides and mounted. 



135. Fastening sections to the slide. 1. Celloidin sections. 

 Sections cut by either the alcohol or the clarifier methods may be 

 conveniently fastened to the slide in the following manner: 



If the sections are transferred to the slide from clarifier or clearer, 

 absorb the fluid thoroughly by placing over the section some absorbent 

 paper and pressing it down gently and firmly, repeating the operation 

 several times with fresh paper. After the oil is well absorbed, with 

 a pipette drop upon the section enough ether-alcohol to thoroughly 

 wet it. This softens or dissolves the celloidin and on its evaporation 

 the section sticks to the slide. Allow the ether-alcohol to evaporate 

 until the celloidin has again set and the surface of the section looks 

 dull or glazed and then place it in a jar of 95% alcohol. Do not let 

 the sections dry. 



If the sections are in series, it is better to put the ether-alcohol 

 on one end of the slide and let it run quickly over the sections and 



