394 Special Procedures III (chap. 24) 



Cellulose Tape Mounting. Palmgren {1954) 



This method has been devised for problem sections, such as tissues 

 containing a large amount of yolk, chitinous material, hard tissue which 

 breaks away from soft parts and falls out of sections. Cellulose tape 

 (Scotch Tape) is pressed firmly on the section surface of the paraffin block 

 or the tissue frozen on the freezing microtome. The sticky surface of the 

 tape attaches to all parts of the section and prevents its wrinkling or 

 shattering during sectioning; 1 -micron to 100-micron cuts will perform 

 equally well. Using this method PalmgTen has cut whole adult mice for 

 radiography on the freezing microtome \vithout loss of parts. The sticky 

 material is soluble in xylene so the paraffin cannot be dissolved while on 

 the tape, making it preferable to transfer the sections to a glass slide or 

 plate. 



procedure: 



1. Mount section and tape with section-side upwards on glass. Hold 

 it in place Avith small strips of tape, but do not cover the section. 



2. Spread a thin layer of 0.5% nitrocellulose over the section, but 

 not over the tape. Let dry. 



3. Immerse in xylene in a petri dish, and leave until the nitrocellu- 

 lose film and section can be loosened easily from the tape. Leave 

 in xylene a little longer to remove all sticky material. 



4. Smear clean slide liberally with albumen fixative. Float section on 

 it and press in place. Blot dry. 



5. Transfer immediately to absolute alcohol-ether (1: 1) and leave un- 

 til nitrocellulose is dissolved. Section should be adhering to slide. 



6. Transfer to 95% alcohol, hydrate to water, and stain. 



comments: 



Frozen section either must be dried (for radioautographs) or car- 

 ried from water up to absolute alcohol before the nitrocellulose is 

 applied for histological staining. 



Serial sections can be made by adding sections in sequence to con- 

 tinuous tape, rolled at each end of tissue block. 



Laminated Thermoplastic Mounts. LaCroix 

 and Preiss {1690) 



LaCroix and Preiss describe a practical and simple plastic mounting 

 method for chromosome smears, whole moimts, and cross and sagittal 

 sections. The cellular detail is good and the plastic mounting makes 



