MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



Reagent required: 

 Water wax (Michrome). 



Technique: 



1. Shake off excess water before immersing the pieces of tissue 

 directly into a bath of water wax in the embedding oven at 

 55-6° C. and leave for an hour. 



2. Transfer to a second bath of water wax and leave for an hour. 



3. Transfer to a third bath of wax for an hour, or longer. 



4. Cast the block and leave it to cool in the atmosphere or in a 

 refrigerator. Care must be taken not to allow the block to come 

 into contact with water. 



5 . After cutting sections, float them out on water, which dissolves 

 away the wax, and take them up on slides. 



6. Stain, dehydrate and mount immediately in the usual way. 



Notes: 



(a) Fat, if present, should be dissolved out with several changes 

 of acetone, before the tissues are immersed in the wax. 



{h) Blocks should be kept dry and stored in airtight containers 

 as the wax is liable to take up moisture from the atmosphere. 



MISCELLANEOUS DEHYDRATING AND CLEARING 



REAGENTS 



BUTYL ALCOHOL TERTIARY 



For dehydrating and clearing tissues for paraffin embedding in 

 place of ethyl alcohol and xylol. The reagent is miscible with 

 water and with paraffin wax, and causes less shrinkage and harden- 

 ing of tissue than does ethyl alcohol and xylol. It is also a useful 

 substitute for ethyl alcohol for dehydrating material stained with 

 methylene blue and other dyes which are easily extracted by ethyl 

 alcohol. 

 Techjiique: 



After fixing and washing tissues in the usual manner pass into : 



1. Tertiary butyl alcohol (T.B.A.) 50% aqueous for 1-2 hours. 



2. 70% Aqueous T.B.A. 2 hours to several days. 



3. 85% aqueous T.B.A. for 1-2 hours. 



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