1638 Journal of Applied Microscopy 



9. Allow sections to flatten by placing in water at a temperature of 110° F. 



10. Fix on slide with Mayer's albumen fixative, which should not be over one 

 month old. Remove section from the water by inserting slide with a thin film 

 of the fixative beneath specimen, and lifting gently. Remove excess of water 

 with a dry cloth, care being taken not to touch section. 



Insert slides in a tray ^ and place in the incubator at 98° F. for one to three 

 hours ; they may stand in sunlight the same length of time, or in a warm room 

 two to six hours. (Shrinkage occurs if sections are allowed to dry, especially 

 brain sections, for which one hour is sufficient.) 



11. {a) Dissolve paraffin from sections by filling tray with xylol, which is 

 allowed to remain from one to two minutes. 



(J?) Remove xylol and wash with 95 per cent, alcohol for one minute. 



(c) Remove alcohol and immerse sections with tincture of iodin, which is left 

 from three to five minutes.^ 



(a') Remove iodin and wash thoroughly in running water two minutes. 

 (Water is allowed to run into tray gently.) 



(e) Remove excess of iodin from section by covering slides with 95 per cent, 

 alcohol for one to two minutes. 



(/) Remove alcohol and fill tray with 4 per cent, aqueous eosin (aq. yel.) * 

 allowing it to stand for three-quarters to one hour. 



(^) Remove eosin solution and wash in running water for half a minute, to 

 remove excess of stain. 



(Ji) Fill tray with the methylen blue solution : 



Methylen blue . . . . 1 gram. 



Potassium carbonate - - - 1.5 grams. 



Distilled water - - - - 100 c. c. 



Dilute one to ten at time of using. Stain for one and one-half to two hours, 

 but never over. 



12. Decolorize and differentiate with 95 per cent, alcohol. For this 

 purpose, four to six Petri dishes are partially filled with alcohol ; slides are 

 removed from tray, excess of stain wiped off, and slide placed face up in Petri 

 dish (two slides in each dish). This process usually requires about five minutes, 

 but not over ten, and the section must be examined from time to time under the 

 microscope, care being taken, however, not to allow sections to dry. When the 

 differentiation is complete, the nuclei are a brilliant blue, while the protoplasm 

 of the cells, blood vessels, muscle fibers, etc., are a dull red. Chromatin 

 particles of nuclei should stand out distinctly in well stained sections. 



1 3. Transfer to absolute alcohol contained in oblong glass tray, large enough 

 for one specimen (tray being kept covered), for one or two minutes. 



Transfer to xylol after removing excess of alcohol. Clearing should take 

 place immediately if sections are dehydrated sufficiently. When economy must 



2. This tray is made of copper, with corrugated sides, and may hold from six to twenty-four 

 slides. In laboratories where specimens from an entire autopsy are carried through, trays con- 

 taining twenty-four or more slides are desirable. 



3. This is to remove excess of corrosive sublimate when used in the fixing reagent. 



4. This and the above solutions may be used again and again, providing the strength is not 

 allowed to deteriorate. 



