122 



THE ART OF MAKING MICROSCOPE SLIDES 



Defects 



Table 1 — (Continued) 



Fig. 75. Object breaks away from wax or 

 is shattered by knife. 



Fig. 76. Ribbon splits. 



Possible Causes 



1. If object appears chalky and 

 shatters under knife blade, it is not 

 impregnated 



2. If object shatters under knife but 

 is not chalky, it is too hard for wax 

 sectioning 



3. If object pulls away from wax but 

 does not shatter, the wrong dehy- 

 drant, clearing agent, or wax has 

 been used 



Remedies 



1. Throw block away and start again. 

 If object irreplaceable, try dis- 

 solving off wax, redehydrating, re- 

 clearing and re-embedding 



2. Soak block overnight in pheno- 

 glycerol mixture, rinse thoroughly, 

 and dry, or spray section between 

 each cut with celloidin, or dissolve 

 wax and re-embed in nitrocellulose 



3. Re-embed in suitable medium, 

 preferably a wax-rubber-resin mix- 

 ture. Avoid xylene in clearing mus- 

 cular structures 



Possible Causes 



1. Nick in blade of knife 



2. Grit in object 



Remedies 



1. Try another portion of knife-edge 



2. Examine cut edge of block. If face 

 is grooved to top, grit has probably 

 been pushed out. Try another por- 

 tion of knife-edge. If grit still in 

 place, dissect out with needles. If 

 much grit, throw block away 



