Cleaning, Labeling, and Storing Slides 



There is not much point in going to all the trouble and difficulty of making 

 a good microscope slide unless one is also prepared to finish, label, and store 

 it properly. There is a great deal of difference between a slide which is merely 

 left after the coverslip has been placed on it with a label stuck roughly on the 

 end and one which has been properly finished and properly labeled. This, 

 indeed, is the principal difference between the "professional" slide which one 

 buys from the biological supply house and one which is turned out by the 

 average beginning student. 



There are two stages to finishing a slide. The first of these is to clean from 

 the outside all unwanted mountant and to polish the glass. The second is to 

 attach to it a label which is both neat and permanent. It is easy to remove 

 the unwanted gum mountant from wholemounts if one is using either the 

 medium of Farrants or the medium of Berlese, for it is necessary only to wipe 

 very gently with a damp cloth until the surplus has been removed. If far too 

 much of the medium has been used, so that there is a large exudate around 

 the edge of the coverslip, it is usually better to work in two stages; that is, 

 to remove about half of this exudate one dav and the remainder the next day. 

 The reason for this is that these gums harden only on the outside and, if the 

 whole of the surplus is washed off at one time, there is a grave risk of dis- 

 placing the coverslip. A somewhat different procedure is employed when one 

 is cleaning a slide which has been mounted in the medium of Gray and Wess. 

 This material dries to a tough pellicle which is not water soluble but is easily 

 removed with a knife. The sharp point of a scalpel is run either around or 

 along the edge of the coverslip, and then the surplus hardened pellicle is 

 picked off as a single sheet. The cut must extend all the way through to the 

 glass or the coverslip, with the object attached to it, may come off. How- 

 ever, this is not a permanent catastrophe since one can easily remount the 

 coverslip with its adherent object in the same medium. 



In either case, after the surplus medium has been removed, the slide is left 

 for at least two days to harden, dipped very briefly in a finger bowl of a cold 

 soap solution, and then dried and polished. The slide must not be left in the 

 soap long enough to loosen the coverslip, or the coverslip is likely to be 

 removed when polishing the slide. 



Cleaning wholemounts made in resinous media is a rather different procedure. 

 It is necessary to wait until the resin has completely hardened, hastened where 

 necessary by exposure on a hot plate. Then as much of the surplus as can be 



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