MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



deteriorates after a few weeks. If negative results are obtained the 

 stain should be checked by staining a section known to contain 

 glycogen. 



Solutions required: 



A. Ehrlich haematoxylin. 



B. Best's carmine stock solution . . lo ml. 

 Methyl alcohol, pure . . . . 15 ml. 

 Strong ammonia solution . . 10 ml. 



Note: This solution should be prepared immedi- 

 ately before it is required for use. 



C. Celloidin 1% in equal volumes of 



absolute alcohol and ether. 



D. Absolute (ethyl) alcohol . . . . 80 ml. 

 Absolute (methyl) alcohol . . 40 ml. 

 Distilled water . . . . . . 100 ml. 



Technique: 



1. Tissues are fixed in Bouin Fluid and embedded in Celloidin 

 or in paraffin wax. If Celloidin sections are employed proceed as 

 from stage 5 (below). If paraffin sections are used the procedure 

 is as follows: 



2. Float sections on the slide with 70% alcohol; flatten out; 

 then remove excess alcohol with filter paper and blot carefully but 

 thoroughly. 



3. Remove paraffin wax with xylol in the usual manner. 



4. Wash with absolute alcohol as usual. 



5. Transfer the slide to a stoppered staining jar containing 1% 

 Celloidin (Solution C, above), for fifteen minutes. 



6. Transfer to a stoppered jar containing 70% alcohol, after 

 rapidly wiping off the Celloidin from the back of the slides. This 

 operation must be carried out quickly so that the Celloidin is not 

 allowed to dry. Leave in the alcohol from ten to fifteen minutes. 



7. Transfer to Ehrlich haematoxylin and allow the stain to act 

 from two to ten minutes, differentiating if necessary with acid 

 alcohol, controlling under the microscope. 



74 



